I'd hate (obviously) to jump to any conclusions as to what happened here ...
BUT, this is the third picture of a CRJ that I've seen on its back with its gear sticking up, and the previous 2 were both ice related on takeoff.
The CRJ has a SUPER critical wing, and is VERY prone to stalling issues with ice ...
Looking at the pics, I'm very glad (and very surprised) that they all got out !