INDIANAPOLIS -- A firefighter says he fatally shot a man who shot and robbed him in the firefighter's vehicle on the city's west side Monday night, according to police.

Aaron Thomas, 28, told police he was giving Shawn Reed, 19, a ride in his vehicle when Reed began acting strangely. Thomas stopped the car in the parking lot of the Family Video at 2940 Georgetown Road at about 10:40 p.m., and Reed pulled out a gun and demanded money, police said.

Thomas said he surrendered his money but then was shot in the chest as he struggled with Reed over the gun in the car, according to police.

Thomas told investigators he then took the gun from Reed and shot him, police said.

"He was able to wrestle the gun back from this guy and end the fight there," Indianapolis police Sgt. Matt Mount said.

Police were called, and officers found the wounded men in the parking lot. Reed was pronounced dead there, police said.

Thomas was taken to Methodist Hospital, where he underwent surgery and was listed in serious condition Tuesday, officials told 6News' Julie Pursley.

Information on why Reed was riding in Thomas' vehicle wasn't available. Police said they were trying to determine whether Thomas and Reed knew each other.

Thomas spoke to his fellow firefighters on Tuesday morning, Indianapolis fire Capt. Gregg Harris said.

"We definitely believe there's going to be a full recovery and he'll be back with us fighting fires and saving lives and doing the things that he was put on the earth to do, and that's help other people," Harris said.

Thomas has been with the Indianapolis Fire Department for five years.