A gunman who opened fire inside a Tumwater, Washington, Walmart and injured at least two people during carjacking attempts was fatally shot by one of two armed civilians confronting him Sunday evening, according to police.

Police were still piecing together the full story of the events that began about 5 p.m. Pacific Time in the town just south of Olympia when they received a call about a possibly drunk driver heading the wrong way on a main road near a local high school, said Laura Wohl, Tumwater police public information officer.

As police sped to the scene, they received a second call about a carjacking with shots fired. When officers arrived there, they found a 16-year-old girl with unspecified non-life-threatening injuries but no suspect. They quickly located the stolen car, but once again no suspect.

At about 5:30 they started getting numerous calls of shots fired in and around a nearby Walmart. Wohl said they later confirmed that the man doing the shooting was the same person involved in the carjacking.

She said the man entered the Walmart, fired shots at a display case and then went into the parking lot.

There he attempted to carjack another vehicle, shooting an occupant in it at least twice. Apparently frustrated in his effort, the gunman then attempted a second carjacking.

At that point, she said, two armed civilians in the parking lot confronted the suspect, one of whom shot the man dead.

Police did not identify any of those involved in the incident or the type of weapons used, except to say they were handguns. The victim of the second carjacking attempt was in critical condition at Harborview Hospital.

The action inside the store set off fears of a possible mass shooting. Indeed, local media reported that the fire department alerted them to a "mass casualty" incident.

Kailani Bailey told the Tacoma News Tribune she was shopping inside the grocery section of the Walmart when a tall man in a T-shirt and jeans ran in and shoved people out of the way, ordering them to "move, move." Then she heard a popping sound from the other side of the store and someone yelling "run, run." When she got outside, she said she heard more shots.

Caitlyn Wallner told the paper a similar story. She heard "pop, pop, pop," and a man yelling "there's a guy shooting. Everybody run."

"There were all kinds of people running out," Robert Berwick, who was in the back of the store, told the Seattle Times. Darren Gossler told the News Tribune he saw a man with what appeared to be a handgun.

The action then moved into the parking lot.

Witness Brian Adams told KING5 TV that "this guy was randomly firing" both inside and outside the store. He said he heard about 15 shots.

Witnesses told the Seattle Times that at least three civilians pulled guns in the parking lot. Police reported just two, one of whom fired at the suspect and killed him.

"He is a hero," Brian Adams told KING 5. "If this customer hadn't done what he did, who knows what would have happened."

Wohl said no other suspects were being sought.

--The Washington Post