COLUMBUS, Ohio -- The suspect in the Ohio State University attack rammed his car into a group of pedestrians before using a butcher knife to cut several people, university officials said.
At least nine people were hospitalized, including one in critical condition. "Victim injuries include stab wounds, injury by motor vehicle and other injuries that are being evaluated," OSU said.
The suspect was an 18-year-old of Somali descent who lived in the area, a federal law enforcement official said. Investigators have identified the suspect but have not publicized his name, the official said. The car used in the attack was registered to a family member.
A US official said the suspect was a legal permanent resident.
Student Jacob Bower said he saw the attacker outside between the Koffolt Laboratories and Watts Hall.
"He pulled a large knife and started chasing people around, trying to attack them," Bower, 20, told CNN.
"Luckily there were so many people, he couldn't focus on one target. I didn't see anyone get stabbed, but I saw the police officer take down the stabber. He waited 'til everyone was clear, and the stabber clearly wasn't stopping. (It) took three shots to take him down. (The) stabber had a crazy look in his eyes."
The officer fatally shot the assailant, eliminating the risk to students, authorities said.
Now, as nine people try to recover from their wounds, investigators are trying to determine a motive, and whether the attack is terror-related.
"We have to consider that it is that possibility," Columbus Police Chief Kimberley Jacobs said.
"We had an attack earlier this year with a man with a knife causing multiple injuries. So we're always aware that that's the potential. And we're going to continue to look at that."
How it happened
At 9:52 a.m., the assailant drove over a curb and struck pedestrians near Watts Hall, OSU Police Chief Craig Stone said.
"He got out of the vehicle and started using a butcher knife to start cutting pedestrians," Stone said. "Our officer was on scene in less than a minute, and he ended the situation in less than a minute."
But as the chaos unfolded, university officials reported an active shooter incident at Watts Hall, the university's materials science and engineering building.
"Buckeye Alert: Active Shooter on campus. Run Hide Fight. Watts Hall. 19th and College," OSU Emergency Management tweeted at 9:56 a.m.
It's possible the gunshots heard came from police trying to stop the attacker, a federal law enforcement official said.
Throughout the attack, the assailant didn't yell or say anything, Bower said.
"He was completely silent, which was very creepy. Not even when he was shot (by police)," the student said.
"The cop that subdued the guy with the knife saved so many lives today."
Stacking chairs for safety
While students waited to hear word on the attacker's movements, some piled chairs against a door to block him from getting in.
"I'm safe in a barricaded room," Harrison Roth tweeted. "If you're on campus, get in a room and stay safe."
Ohio State's Columbus campus is colossal, one of the largest in the United States. The university has more than 65,000 students enrolled across the state.
Students had just returned to class Monday after the Thanksgiving break -- and after the OSU football team's big win Saturday over the school's biggest rival, the University of Michigan.
Michigan's athletic department tweeted its support for Ohio State, saying "Stay safe, Buckeyes."
Students are getting ready for final exams, which begin on December 9.
The incident also comes during the first month of the Ohio State public safety director's job. Monica Moll came to the helm on October 31.
WGN reporter Nancy Loo's daughter Aubrey Jenkins is a sophomore at OSU, and in an interview with WGN, she said she was on lockdown at the French Field House with her cheerleading team. She is safe.
This is a developing story. Check back for details.