(RNN) - Three people are dead and one is injured after a man opened fire on holiday shoppers at a crowded mall in Portland, OR.
Police confirmed the unnamed gunman died from a self-inflicted gunshot wound.
Officers have tentatively identified the shooter, an adult male, but won't release his name "until we have 100 percent confirmed that identity," said Sgt. Adam Phillips with the Clackamus County Sheriff's Department.
Clackamus County 911 operators first received calls from shoppers at 3:30 p.m. PST after they head gunshots at the Clackamas Town Center mall.
A witness told Portland station KPTV News that the gunman ran through a Macy's department store and entered the food court, where he began shooting.
"The mall is supposed to be a place we can all take our families, feel comfortable that this is a great place, especially at the holiday season. These things aren't supposed to happen," said Clackamus County Sheriff Craig Roberts.
"We train for them. We pray and hope they never do happen."
Witnesses said the man may have fired as many as 60 shots, suggesting he was carrying a gun capable of carrying a large amount of ammunition and firing at a rapid rate.
Police commended citizen heroes, shoppers who also happened to be ER nurses and a physician who provided care to the wounded.
Four SWAT teams swept through the 1.4 million square feet of mall looking for the shooter and to confirm there were no other gunmen involved.
"By all accounts there were no rounds fired by law enforcement today in the mall," said Lt. James Rhodes, a spokesman for the Clackamas County Sheriff's Office.
Krysta Brunelle, 16, was Christmas shopping for family at the mall Tuesday afternoon. She and a friend were taking a break at a Jamba Juice in the food court when the shooter opened fire.
"I didn't know the shooting happened at first. I thought it was balloons popping," she said.
"After the fourth shot, we dropped to the floor and tried to hide behind the counter. We heard screams and saw people running. I left my keys on the counter and we ran."
Brunelle and her friend made it out safe. Her keys and wallet, along with her backpack, are still in the mall.
"The shots were boom, boom, boom, shot after shot. It was the scariest thing I've ever been through in my life."
"The shots sounded like they were right in your ear."
After getting out of the mall safely, the two hopped in her friend's car, said a prayer and drove to their school nearby.
"What ran through my head was 'I didn't tell my dad I loved him this morning before he left' because he was sleeping … I told him, but he was asleep. He later told me he had heard me and that he knew," she said.
The shooter is described as a man wearing all black clothing with a white hockey mask and carrying an AR-15 rifle.
Officials do not believe there were other shooters involved.
John Canzano, a sports columnist for the Portland Oregonian who was at the mall when the gunfire broke, reported through his Twitter account that mall security ordered all stores' caged gates closed.
All entrances to the mall were blocked off and the mall will remain closed through at least Wednesday.
Late Tuesday, police were in the process of making a final sweep, clearing the mall store by store, looking for shoppers still in hiding.
Oregon Gov. John Kitzhaber issued a statement soon after news of the shooting broke, offering his assistance to the mall patrons.
"My thoughts and prayers are with the victims and their families. I appreciate the work of the first responders and their quick reaction to this tragic shooting," said Kitzhaber. "I have directed State Police to make any and all necessary resources available to local law enforcement."
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