Exploding capacitor

The first dangerous situation occurred during work on the software. One of the capacitors on the control unit exploded and made 1cm red dot on my hand. It exploded when I was moving my hand to power off button.
No over current or something like that. It just explode without no reason. I suspect that it was damaged (it had a little bulge). Originally it was part of the old PC power supplier.
Capacitor after explosion: Capacitor on control unit after explosion.