You could, however, speak with the buyer or the landlord and perhaps make an arrangement to take over. However, the landlord will probably want back rent.
As for whether you are liable for the unpaid rent, it depends. If you are still on the lease and just assigned it over the the buyer, chances are you are still liable even though the buyer filed for bankruptcy. His bankruptcy protects him and not you. If a new lease was signed by the buyer, you don't have to worry.
For more questions, please contact (213) 637-1333.