A man was shot and wounded in the lobby of the San Pedro post office this morning. Police have surrounded a nearby residential complex where they believe the shooter has fled. Officers say neither the victim nor the shooter are postal employees. The victim is undergoing surgery and is in serious condition. Postal Service spokeswoman Terri Bouffiou says the mid-morning incident appears to have started as an argument between two people. She says the two were arguing when they walked into the lobby. Arais Madan, supervisor of customer service at the post office, was in a work area behind the lobby when she heard a single gunshot. She says an employee who was working in the lobby came running to the back. That worker said that when the shot rang out, a female customer jumped over the counter and said she was in the line of fire. About 70 people work at the facility, including 57 letter carriers. Three employees were working the customer windows at the time.