I just had some preventative work done on my car ( serpentine belt replaced and a valve that was sticking causing a whistling noise) and got it back 3 days ago. It's been sitting for a day and a half and today when I drove it I noticed water leaking underneath. When I looked under I saw this crack. No one mentioned it at my last oil change 2 weeks ago, so I find it strange that now there is just a huge crack underneath. It was a new mechanic I used so I don't really trust him and I worry he may have damaged it. Does anyone know what's causing this leak? Thanks!

The leak is coming from right above the pedal above the Rusted pipe

Here's the cracked zoomed in on. You can see the dark wet spot where the water is leaking