Multi-family fire damage

[Curtis W. Sutherland]

My all cash offer was accepted on a 38-unit apartment this week. The property had four units that were recently damaged by fire. 

When the seller sent the contract, there is also a release of lability that he wants me to sign. 

He says there is no pending law suits that he is aware of. That concerned me. Then to release him from any past or future environmental issues really concerned me. 

What issues do I need to know about before I pay for this property?