99 accord coupe ex v6

The other day I was just leaning back in my drivers seat and i heard a popping sound and the front left part of the seat came up. the driver's seat is power so it can still move up and down on the rails and also i can lean the seat back and forth. i looked at the bolt and its still down so it just came off the rails or something? does anyone have any experience with this or what it is going to cost to fix it?