Let me just get right into it.
Firstly, we should check Apache/Nginx/IIS web server logs and make sure they aren't the ones causing the crash, if they are then we'll simply patch them up and get them up and running.
If that didn't work then we need to check the Operating System logs whether it's Windows or Linux.
If it's Windows we'll check the Event Logs and if we're on Linux we'll have to go through everything in /var/logs and /var/tmp
By doing so we'll know exactly what's going on with the Operating System, it could be corrupted files, some services could be causing trouble, it could be a malware or anything similar.
It's very important to us to make sure we KNOW the cause of this crash, not just fix it, because we have to prevent it from happening again.
I've done this before, I know what I'm doing and I'm good at it; let me handle this.
PS: I'm Lebanese, French is my second language so you don't have to worry about communication at all.