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...
Ada is an interesting language (we were taught it as our first language at uni), but it's not free from safety issues.