SHOOTING SPREE: Washington State Gunman Wounded 2 & Customer Killed Gunman

TUMWATER, Wash. - A Walmart customer is being hailed as a hero Monday after he killed a gunman who injured two other people during a wild panic in Tumwater on Father's Day .

Customers ran for cover Sunday as the gunman opened fire inside the store, then tried to carjack a vehicle at gunpoint outside in the parking lot.

"We all just dropped our stuff and ran for our lives," says Caitlin Wallner, who was at the checkout when the suspect opened fire.

"It's like an earthquake - you just got to get up and haul ass and run," said another woman who was there.

But one customer stood his ground and grabbed his own weapon, killing the gunman.

"He is a hero," says Brian Adams, who was at the scene and saw the Walmart customer pull out his own weapon and shoot the gunman. "I really think more people could easily have been shot with what this guy was doing. He was just - there were several shots."

The bizarre drama actually began earlier, around 5:30 p.m., with a report of a drunk driver going down the road the wrong way near Crosby Road.

As officers arrived on the scene, they received another call reporting a carjacking and shots fired near Israel Road and Tyee Drive. There, officers found an injured 16-year-old girl but no suspect. Her injuries were not life threatening and she is expected to be OK.

Shortly afterward, a man believed to be the carjacker showed up at the Tumwater Walmart store in the 5900 block of Littlerock Road SW and opened fire at a display case, police say. The gunman then went outside into the parking lot and fired more shots.

Megan Chadwick was there, huddled with her four kids as the shooting started.

"I thought we were in the clear as soon as we got out, and then I just heard four gunshots in a row, the cars crashing and the carts flying at us," she says.

The gunman tried to hijack a car - but when the driver refused to give it up, the gunman shot him. It was then that Adams saw another Walmart customer jump into action and shoot the gunman dead. Two other customers also reportedly pulled their weapons in case they were needed.

"Those men who stood up, they are heroes to me," says Chadwick.

The identity of that hero customer who shot the gunman has not been released.

The carjacking victim who was shot by the gunman was airlifted to Harborview Medical Center in Seattle, where he is listed in critical condition.