Three employees were shot and wounded on Wednesday night at a church in Otay Mesa, California, the San Diego Police Department said.
One of the victims was killed and the other two were in stable condition after being transported to hospital.
Detectives search for the gunman who entered the restaurant and ordered food, the statement said. He left the restaurant after arguing with the employees and came back with a handgun.
He shot the three employees, a woman and two men. According to the statement, no customer was hurt.
The suspect is still on the run and was last seen in a dark colored sedan.