> officers and witnesses heard a broadcast coming from the RV giving a dire warning: “Evacuate now. There is a bomb. A bomb is in this vehicle and will explode." Then, the voice started a 15-minute countdown. Metro Police Chief John Drake said the six officers at the scene quickly began to evacuate the area, going door-to-door. They redirected a man walking his dog along the street.

This is surreal. Almost a scene from some Sci-Fi spy movie, in which the protagonist/antagonist performs a surgical attack on a strategic target while preventing unnecessary civilian death...

Was pretty common (though not consistent) for the IRA to phone ahead to warn where they'd put bombs.

Ironically it was on an occasion when a bomb was phoned in that led to the single biggest atrocity during the troubles. 29 people killed by a cat bomb in Omagh. We may not be living in peace today has it not happened

“The Omagh bombing was a car bombing on 15 August 1998 in the town of Omagh, County Tyrone, Northern Ireland, United Kingdom. (...) Telephoned warnings had been sent almost forty minutes beforehand and police inadvertently moved people toward the bomb.”

https://en.m.wikipedia.org/wiki/Omagh_bombing

*car bomb

Probably a car bomb. The IRA were infamous for those.

Thanks. Apparently it's no longer cool to ask questions on HN, since I had no idea what a cat bomb was, yet a mod flagged it regardless.

Common sense would tell you the t and r keys are right beside each other

Surely a cat with a bomb in it.

It was probably plan #513 on how to kill Castro.

Notes: Put bomb in cute cat. Castro is known to pat strays three times. Use that as the trigger.

You can't prove I'm wrong: https://en.wikipedia.org/wiki/Acoustic_Kitty

Local TV News managed to interview a neighbor from directly across the street where the explosion occurred[1].

[1] https://www.youtube.com/watch?v=iag6cTWpgq8

Interesting things to consider.

1) I heard something about "fake reports" about gunshots. But maybe the perp shot off some guns just to get the cops to show up?

2) This woman stuck around for 15 minutes or a half hour while this thing was saying "you need to evacuate, this has a bomb"???

3) This woman recalls a male voice but the news played a female voice. This goes to show how bad our memories are!

Maybe she was right, and there were two voices? The female announcement sounds like it was edited. Badly. This might explain the strange verbiage as well ("All buildings" stands out. That particularly phrase, with its inflection, sounds like it originally came from the end of a sentence too). I've heard other people say it sounds like the same voice used by the city during the summer protests or something along those lines.

For the purposes of arguing, let's say someone got ahold of some municipal evacuation recordings and chopped them up for this. It's not likely they had enough phrases to warn people a bomb would be going off in specifically fifteen minutes.

EDIT: For anyone curious about other instances of bad edits, listen to the word "this"; there's another word before that, and it was cut off: "thi-this area must be evacuated now". Also, "if you can hear this message, <unnatural pause> evacuate now." It's not likely any professional voiceover person would announce this way, nor would anyone who's paid attention to basic edits before consider this passable.

If this is all true, I guess the next question to ask is who would have access to those announcements, and who would think to use them? Most people would probably just use some text-to-speech thing unless it was easy/they had good reason. I'm probably overthinking this, though.

Looks like it may be Microsoft Anna text-to-speech. The poster added reverb and echo and it was very, very close to the youtube security video that captured the warnings. The device that recorded that may have also skipped on its own recording and may not be perfect.

https://www.youtube.com/watch?v=8B--BNdnuvA

The original video:

https://www.youtube.com/watch?v=5nygTJeu9fU

This is probably a much more likely explanation; we'll see when we get bodycam footage or anything else if there's a better recording of what was being played. But for whatever it's worth, most TTS engines are modeled around well known voiceover people.

It's still possible that since the engine didn't reproduce a 1:1 copy and there's no discernable (at least to me) artifacts in the one copy of sound footage we have, that was the real person, and she just announced it slightly differently.

The audio equivalent of writing a ransom note with magazine clippings!

> This woman stuck around for 15 minutes or a half hour while this thing was saying "you need to evacuate, this has a bomb"???

Watching a video, the audio was so surreal I had to ask myself how I would respond if I heard that without any clue where it was coming from.

Hopefully I never find out, but I guess now I'm a bit more mentally prepared to not linger.

Re 3, here's some more examples:

"How Many of Your Memories Are Fake?"

https://www.theatlantic.com/health/archive/2013/11/how-many-...

"Reliability of Eyewitness Reports to a Major Aviation Accident":

https://commons.erau.edu/cgi/viewcontent.cgi?article=1040&co...

> 3) This woman recalls a male voice but the news played a female voice. This goes to show how bad our memories are!

Here is the recording: https://www.youtube.com/watch?v=5nygTJeu9fU

I actually also watched the video before reading that it was a female voice and also thought it was male.

Holy shit I think the same thing happened to me. Maybe this is one of those perception quirks rather than a memory quirk.

Listening again, I could see it being a man with a voice like David Sedaris.

There were gunshots sounds but we're not sure if it was audio from the RV or actual gun shots

Does Nashville use Shotspotter? I wonder what the frequency range of their sensors is (I would guess a real gunshot would have pretty different spectral range from a speaker).

This makes for such a fascinating story. Supervillain type stuff. Except fortunately in this case a supervillian with some sort of code of ethics.

Let's not idolize crazy. Fascinating, yes. But supervillains have redeeming qualities. There's nothing redeeming about a car bomb.

Defined agree that this was a heinous act.

But it seems this person or group of people took multiple measures (Christmas morning, gun shot sounds, verbal notice of intention) to make sure civilians had notice and time to get to a safe distance.

Just seems a bit odd and unprecedented that an act like this was carried out with explicit intent to minimize civilian harm and casualties.

Will be interesting to hear more about what actually happened, by whom, and their motives, if any of this ever becomes known.

It's very much precedented. The IRA would provide warnings for their bombings, with varying levels of success in averting civilian casualties.

Well playing a warning and picking a time and place to minimize casualties is some kind of redeeming. It would certainly be worse if they tried to kill people, picking a crowded place and time.

I guess. I'm just sad I lived to see a second legit terrorist attack on American soil. I remember being in 8th grade when sept11 happened.

I think there have been several attacks of this magnitude or worse since September 11. e.g. The Boston Marathon bombing or the anthrax attacks, or Christopher Dorner (though maybe that's less terrorist and more revenge). There have been lots.

I think, so long as this wasn't a test run for a coordinated attack on the telecoms, then this is not a very bad terrorist attack.

It's a weird thing about our recall bias that this thread hasn't mentioned any of the mass shootings that have taken place in recent memory. A few that come to mind are the shootings at the Charleston church, the Tree of Life Synagogue, El Paso, and the Pulse Nightclub. None reached the scale of 9/11 but there's been a parade of horrors since 9/11.

Yeah, that’s a good point. I forgot entirely about the Boston marathon bombing. And in comparison, that one was indeed much worse... my Airbnb host at the time was participating in the race, and almost got caught in the explosion.

Hmm. Well, it will be interesting to see whatever motivated this bombing.

That's not even counting the hundreds of officially sanctioned terror attacks by US police in that time.

Also, from the 9/11 and anthrax era, the DC area sniper shootings.

> I heard something about "fake reports" about gunshots. But maybe the perp shot off some guns just to get the cops to show up?

Reports of gunshots weren't fake because multiple witnesses heard gunshots. No idea if it was related to the bombing or not.

Example:

https://www.cnn.com/2020/12/25/us/nashville-explosion/index....

>McCoy said he was originally woken up by what he believed were gunshots prior to the explosion. He got up and looked out the window, he said, but went back to bed when he didn't see anything. Asked if the noise he heard could have been something other than gunfire, McCoy emphasized that he believed it was, saying he owns a gun and goes shooting, so he's familiar with the sound of gunshots.

The prevailing theory is that there were no gun shots, but gun shots were played over the speakers to wake people up so they would evacuate.

Why ammo in RV then?

Perhaps the RV was stolen from an American.

That voice announcing evacuation sounds very professional, not like a computer synthesized voice... I wonder if they will try to trace that.

Many of the current neural net voice synthesis engines are fantastic and sound extremely real. Amazon Polly for instance. I'd punch in the phrase and do some comparisons, but given the attention those logs will certainly get maybe I won't.

Neural net synth would be even easier to trace. It’s quite hard to set up an aws account via untraceable currency and an untraceable phone. I did it when I was 25 or so, and it took about three weeks of planning and execution just to get the cards and phone.

Given the sophistication of the attack, I wouldn’t say it’s impossible they have neural net experience. But as someone who spent a good chunk of time trying to get Dr Kleiner to sing (https://m.youtube.com/watch?v=koU3L7WBz_s) it wasn’t remotely easy a year ago to do this locally.

Using “say foo” in macOS would’ve been the most straightforward solution, I think.

The same difficulty of anonymity arises with the RV itself, a very ostentatious vehicle that not only can be traced with ease, it can be tracked retroactively on virtually every street, every highway, etc.

Regardless, for all we know the person isn't concerned with being caught (and may currently be deceased given that possible human remains have been found).

I bet you could buy one with cash on Craigslist pretty easily though

You're right. I retract my comment; it was fundamentally mistaken.

> it can be tracked retroactively on virtually every street, every highway, etc.

Not virtually. Actually.

NSA et al can do - will they publicly tip that hand for this?

No need to publicly tip your hand. Just follow that trail of evidence, then use parallel construction to produce a different trail that you reveal publicly.

> Not virtually. Actually.

"virtually" also means "almost", which is what GP was using it for.

Are you a bot? Because your profile makes me think you're a bot. I mean no disrespect.

Some say I am, but I like to think there's a little bot in all of us.

>given the attention those logs will certainly get maybe I won't

Siri, detonate this bomb in incognito mode

Look at that chilling effect go!

Seems to be Microsoft Anna:

https://www.youtube.com/watch?v=8B--BNdnuvA

My theory, and the most untraceable way to do it today, would be to use recordings out of movies or video games, there must be dozen of them available.

Unless you have those movies and video games already on your hard drive, downloading them will create a log somewhere that could be traceable. :/ Windows TTS on a device not connected to the internet is a better choice. (I don't know why we are trying to give them ideas!)

No need for the games you have all the material on youtube.

That's my point. If you go search on YT for those videos, you're leaving a digital trail that can be easily traced back to you.

Simply using the "say" command on a mac would work.

If they do, it will be a case of no good deed going unpunished.

It's a good deed that they broadcast this message?

Why a rational human would broadcast this message-

a) The penalties if there were deaths would be much, much more severe. The manpower involved in the hunt would be exponentially larger.

b) They have some other goal that would be sabotaged if there were deaths.

c) They have morality and can rationalize bombing buildings, but not killing people.

This isn't a "good deed". It's a presumably rational person playing the situation.

Isn't acting out of a sense of morality the definition of a 'good deed'?

Granted, bombing stuff hardly classifies but if you decide it's necessary to bomb something, preventing unnecessary harm for moral reasons could still be seen as a 'good deed'.

No. Some people think killing Jews is moral, for instance.

Most violence that gets carried out is for purposes the perpetrator considers moral whether it's "snitches get stitches" or "They cheated on me" or "His friend killed one of my friends and this is just vengeance."

Yep, as long as you can explain that someone is a bigger monster than you are you can justify yourself killing anyone.

Indeed, but isn't that actually an argument for what constitutes a 'good deed' being highly subjective, since moral frameworks seem to be?

>This isn't a "good deed". It's a presumably rational person playing the situation.

Why not both? A deed can be both good and rational.

Reducing the harm of a purposeful, voluntary action -- maybe just to make it personally palatable to your own morality or mission -- doesn't seem to meet the threshold for a "good deed".

Less of a bad deed, sure. But given that they still did the very dangerous thing, no not a good deed.

The context I replied to implied that tracking a bomber by a warning they gave would be "punishing" a "good deed". That seems dubious.

>The context I replied to implied that tracking a bomber by a warning they gave would be "punishing" a "good deed". That seems dubious.

Oh yeah, sorry, I missed the context. It's a good deed, but not good enough to outweigh, you know, bombing. The recording should be traced like any other part of the bomb.

Somehow the warning made it terrifying for me. Just an explosion with no warning would’ve been more normal to me somehow. It feels like a video game level where you have a countdown to solve a puzzle and you’re trying to save someone or something from the explosion.