My RB Rosco and Dusty were like that. I was taking the both of them to obedience classes, but on seperate nights. One or the other would literally break the fence down. I'd come home and they'd be sitting in the driveway waiting for the other one. I wound up having to crate them if I had them seperated so that they wouldn't damage themselves or anything.

Dusty was very very very depressed when I put Rosco to sleep. That is the main reason why I got Roxy within days of putting Rosco down.