I't more like mud than lava. Anyway, it can be very dangerous. My family is from the north west of Arentina (Jujuy). In some areas there is a somewhat similar problem that is not caused by a volcano, just unusual heavy rains that create mud. We even call it "Volcán" (volcano).

There was a big disaster a few years ago [1], but smaller one are usual and they have to rebuild the roads and bridges from time to time.

[1] Some news coverage in Spanish https://www.jujuyalmomento.com/alud/siete-anos-la-tragedia-v...

It seems to me that years ago people would point out a stretch of dead trees killed by a mud flow from Mount Rainier.

A lahar was the cause of a deadly railway accident in New Zealand about 60 years ago: https://en.m.wikipedia.org/wiki/Tangiwai_disaster

In other words, a Lahar flow. Pretty common in the Philippines, I've seen a few while on that country.

This is definitely not “cold lava”, which isn’t a thing. It’s just mud from a lahar flow. When it is fresh and moving, it can be very destructive like a river of concrete.