Updated

Police say it appears an unarmed man was fatally shot while trying to intervene in a dispute between some relatives and two on-duty city sanitation workers.

Al.com reports that 42-year-old Larry Duncan was killed by gunfire Sunday morning in Birmingham, and that his wife's cousin and one of the sanitation workers were wounded. Police say both of the wounded are expected to survive.

It wasn't immediately clear what prompted the dispute, and police say they're investigating why it ended violently. Police say Duncan wasn't carrying a weapon and didn't fire any shots.

Birmingham police Sgt. Bryan Shelton said it's not clear why an on-duty city employee had a handgun on the job. He didn't identify the worker or give other details, and no charges were immediately filed.