Why did this massive hump suddenly appear in my floor?

The house is over 100yrs old but was redone in the late 40s/ early 50s. The dip on the left in pic 1 was slightly there but now it s worse and literally almost overnight this huge hump appeared.

House is pier and beam, the joists run the direction of the level. I put my camera on a pole and got the other pics of the area. Obviously there’s a collapsed footing, but that doesn’t look recent to me.

Unfortunately it’s very difficult to crawl under the house so I haven’t done more than take these pics. It was hard to maneuver the pole to get more but I’m going to figure something out. I was waiting for it to stop raining to crawl under here. (Rain started after the hump appeared.)

I’m in south Louisiana FYI. Thanks!