My 2 friends signed a lease meant for 3 people and now want to back out of it. Is this possible?

My friends found an apartment that they wanted to live at a few weeks ago. The realtor told them that there were dozens of applicants willing to sign the lease and live there, so they went ahead and signed the 3-person lease as 2 people and paid a $2100 deposit. Now, 2 weeks later, the realtor told them that there are 0 other applicants. They want to move in with me at a different apartment that I found. Is it possible for them to back out of the other lease? Is it possible to get their deposit back?