My buddy actually owns the building (business) this happened at. He was leasing some warehouse space to the guy that was building this guacamole packing rig. The rig from what I understand was fully built and they were testing it out. The rigs job was to take the guacamole and pressurize it, then put it into the containers under pressure with zero oxygen so it stays fresh. They were testing the rig out using water as it leaves no mess and something let go causing it to essentially explode. The guy who built the thing was a big dude (like over 3 bills) and he was hit with a chunk of metal that blew about 50 feet away and just smashed his bones to pieces. The other 2 guys got hurt with shrapnel and they were only back there just helping the main guy out to be nice (didn't work for him or with him).
My my wife's cousin that works there heard the explosion and saw the aftermath. Was pretty shaken up seeing how badly the main guy was messed up.
You don't mess with things under pressure. Some of the scariest warning labels I've ever seen were on a concrete pump. All sorts of pressure related amputation warnings. Boiled down if you're standing next to this flange when it let's go it'll cut you in half.