I'm not sure how an Odyssey's seat works, but in my 13 year old T&C, all of the seats "latch" onto metal rings/brackets that are sticking up out of the floor. You can "stow" the third row by unlatching it and flipping it down into the cargo area, and in the case of Chryslers the 2nd rows can also independently stow into the floor. I would assume that in this van perhaps when the seats were last put back into the upright position they either weren't "slammed" down hard enough to securely latch in place, or the latches themselves were going bad/broken, and when he leaned over to reach into the cargo area, the seats came unlatched, dumped him upside-down into the cargo area and landed on top of him. [edit] Once that happens, how a 16 year old male can't push the seats back up into position to get them off I'm not sure, but it must not have been possible.