This was not Ada's fault but the developer team's fault since it used a working Ariane 4 software for Ariane 5 without exhaustive testing. They made the mistake, and blamed Ada for that. The Ada software worked perfectly for which it was written for.
http://compgroups.net/comp.lang.ada/ariane5-faq/1406823
And yes, Ada is still used today.
So how many crashes that happen in programs written in C++ are the development teams fault rather than the C++'s?
Ada is an interesting language (we were taught it as our first language at uni), but it's not free from safety issues.
Crashes due to the language implementation's fault are much more likely in C++ than in Ada. Ada compilers are 100% verified, otherwise they are not allowed to call themselves "Ada compiler". There is no such thing for C++. The safety gap between C++ and Ada is actually so big that we don't even need to talk about that.
The flaws C++ were the reasons why Rust was invented. Mozilla wanted a safe language for the next generation of browsers, and they realized that C++ is not a good choice for safe programming.
Quote: "Mozilla intends to use Rust as a platform for prototyping experimental browser architectures. Specifically, the hope is to develop a browser that is more amenable to parallelization than existing ones, while also being less prone to common C++ coding errors."
Source: https://www.quora.com/Why-is-Mozilla-developing-the-Rust-lan...
Like Ariane 5? :->
The crash was caused in part by failing to catch an exception in Ada.
http://sunnyday.mit.edu/accidents/Ariane5accidentreport.html