Two people were killed and at least one other person was seriously wounded during a Tuesday afternoon attack at Clackamas Town Center's food court area.
The gunman is also dead, according to the Clackamas County Sheriff's Office.
One young woman wounded in the shooting was taken by Life Flight to Oregon Health and Science University Hospital, where she was listed in serious condition.
The mall was closed Tuesday evening as law enforcement began investigating the shooting. The mall's owners, General Growth Properties of Chicago, said the shopping center would remain closed during the investigation.
At the same time, TriMet's MAX station and parking garage will be closed for at least Wednesday. MAX Green Line riders will need to board trains at the Southeast Fuller Road Station. Riders will not be allowed into the Clackamas Town Center Transit Center MAX Station.
Ten bus lines that serve the Clackamas Town Center Transit Center and other bus stops in the mall's parking lot will be detoured during the investigation. The buses will serve temporary stops on Monterey Avenue, near the parking lot entrance by the movie theater, and at the Fuller Road Station. Lines being detoured are 28, 29, 30, 31, 71, 72, 79, 152, 155 and 156.
Locked in for hours
The attack began at about 3:27 p.m., sending nearly 10,000 people scrambling for exits inside the two-level, 1.2 million-square-foot shopping center in suburban Clackamas County, about 12 miles from downtown Portland.
Only one gunman was suspected in the shooting, according to sheriff's office spokesmen. Deputies said that at about 4:45 p.m. the shooter's body and weapon were found inside the shopping center.
They did not provide any other details about the shooter or the weapon, other than it was a semi-automatic rifle.
A sheriff's office spokesman said the "shooter has been neutralized." The gunman apparently died of a self-inflicted gunshot wound.
Sgt. Adams Phillips said law enforcement officers did not fire any shots during the incident.
Gov. John Kitzhaber dispatched Oregon State Police Superintendent Rich Evens to the mall to help with the investigation. Kitzhaber praised the law enforcement effort to contain the incident and limit casualties.
"My thoughts and prayers are with the victims and their families," the governor said. "I appreciate the work of the first responders and their quick reaction to this tragic shooting."
Sheriff's deputies who arrived within minutes of the first reports on the shooting guided most people out of the mall. Some mall employees locked themselves in break rooms and other places inside the center's more than 180 stores.
Ariel Lihs, a resident of Clackamas who works at the mall, said she heard shots, but thought at first that they were construction sounds. After seeing people flee Macy's and Nordstrom in the northeast corner of the mall, she went directly to her finance, Logan Young, who works at the mall's Hannah Society.
"I got up and ran straight to Logan, and although we've been locked in for two hours, I'm glad I did, because we might not be together now," she said.
A panic situation
One witness told reporters that the gunman apparently entered the mall through a side door near Macy's on the south side of the mall near the center of the main building. The man dressed in black and wearing a hockey mask, ran through the mall before shooting.
Michael Heard, a stylist at Tony and Guy Hair Salon inside the mall, said he was styling a person's hair when the shots started. People in the mall began to run when they heard the shots, Heard said.
"It was kind of like a movie," Heard said. "People were grabbing their kids and running out."
Heard said people could not use their cell phones and the Internet was down about the time the shooting started. Outside the mall, some people received texts from friends in California and other states who heard about the shooting from the news media.
Although police were blocking the mall's main exits, Heard said he and other salon employees were able to go back into the mall twice to shut down their shop.
"It was kind of a panic situation," he said. "There was a big crowd running out."
Don, a Portland man who didn't want to give his last name, was outside the Nordstrom store when the shooting occurred, and said he heard 12 to 18 shots fired in the direction of the food court. He and his wife Phyllis were among the many shoppers quickly shepherded into the Nordstrom cafe for safety.
"Just moments after the shots rang out, they got people inside and closed the gates, almost immediately," Don said.
Looking down the mall, he said, "You could see all of the security gates were going down."
It was a scary experience, Phyllis said. Nordstrom employees helped by serving the people coffee and chocolate inside the stores café. After an hour and a half huddled inside the cafe, they were escorted to their cars.
Loud pops and flash
Several minutes after the attack began, deputies shut the mall down and began searching for the gunman. At one point, there were more than 100 law enforcement officers from the surrounding areas in the mall.
Witnesses told KOIN Local 6 that hundreds of shoppers were told to get down on the floor of several stores shortly after the shooting began. Minutes later, they were told to leave the stores and the mall.
Art Idelbong, an Oregon Air National Guard member, was in the magazine section of the Barnes & Noble bookstore when he heard "loud pops and saw a flash coming from the hallway."
"I looked across at the girl who was studying and we both had a puzzled look when another loud pop came from the hallway," Idelbong said. "We both got up and headed for the front entrance after gathering our bags and umbrellas. Employees and other customers all were grabbing their possessions and heading for the front door."
People said the crowded mall was chaotic as people began to leave the shopping center. Witnesses said they heard what sounded like firecrackers and then were warned to leave the center. Others described the sounds as loud bangs.
Most people reported hearing about a dozen or more shots that echoed through the mall.
Fire trucks, law enforcement vehicles and ambulances were massed at the mall's north entrance near the theaters along Southeast Monterey Avenue.
About 100 law enforcement officers from around the region were still at the mall, some searching the massive shopping center to make certain there was no other gunman.
Macy's employee Karen Reese, a resident of East Multnomah County near Gresham, was just arriving at work as police arrived. Although she was told by management not to divulge who might be killed or injured, she planned to wait out the night until she heard from her co-workers.
"There are just a few of us who aren't accounted for yet, so I'm still really worried," she said.
Pamplin Media Group reporters Steve Law and Raymond Rendleman contributed to this news story.