There are 23 CRJ 900's that are owned by Wells Fargo.
14 others are owned by Mesa.

I am sure that if Mesa could not make the payments on the 23 airframes, US Airways would be happy to take over.
The other 14 would be up for grabs.

There could be more but i don't feel like looking them up.
FAA Registry - Aircraft - Make / Model Inquiry Results

http://registry.faa.gov/aircraftinqu...Val=0&PageNo=1