An Ohio State University student plowed a car into a campus crowd, then jumped out and started stabbing people with a butcher knife before being shot dead by police Monday morning, officials said.
Nine people were taken to hospitals after the ambush, and one was in critical condition. The incident was initially reported as an "active shooter" situation, but the suspect did not shoot anyone.
A police officer was on the scene within a minute and killed the assailant. "He engaged the suspect and eliminated the threat," OSU Police Chief Craig Stone said.
Law enforcement officials told NBC News the suspect's name is Abdul Artan, an 18-year-old student at the university. He was a Somali refugee who left his homeland with his family in 2007, lived in Pakistan and then came to the United States in 2014 as a legal permanent resident of the United States, officials said.
The motive was unknown, but officials said the attack was clearly deliberate and may have been planned in advance.
"This was done on purpose," Stone said.
A campus lockdown was lifted about 11:30 a.m., some 90 minutes after the violence unfolded on the Columbus, Ohio, campus, where 60,000 students are enrolled.
"This car just swerved and ran into a whole group of people," said Nicole Kreinbrink, who was walking down the street when she saw the car hit people who had evacuated an academic building during a fire alarm.
"All these people were running and screaming and yelling," she added.
Jacob Bowers, an OSU sophomore, was sitting on a bench about 100 feet away when he noticed people running.
"Then I heard someone yell, 'He's got a knife.' And I saw a guy with a big-ass knife just chasing people around. When I saw that, I grabbed all my stuff and started running," Bowers said.
Bowers said he looked back to see a police officer on the scene. The officer yelled to the suspect, "Drop it and get down or I'll shoot," and then fired on the suspect, Bowers said.
"The man was going insane," he said.
Another student told NBC News he heard gunfire from his dorm room.
"I heard gunshots from my dorm, probably six or seven," said Stephen Yunker, 18, a freshman who lives two blocks from Watts Hall, where the incident occurred.
He said he and his roommate looked at each other, heard sirens about five seconds later, and then looked out the window.
"We saw fire trucks, couple of cars, and a body laying on the ground," he said.
The Columbus Fire Department said it transported 10 people to hospitals; nine were in stable condition and one was in critical condition.
The campus was put on lockdown for 90 minutes after the university first reported an "active shooter" in the chaos of the moment.
"Run Hide Fight," the university's emergency management office tweeted. "Continue to shelter in place."
Students hunkered down in classrooms with shades drawn across the 2,000-acre campus.
Lisa Goldstein, 26, was in her Geographical Information Systems class in Stillman Hall when a text alert hit everyone's phones. The students blocked the door with their book bags and monitored social media and live streams for updates.
"It's a little overwhelming and scary. It's not something you think would happen on our campus," she told NBC News.
Ohio Gov. John Kasich tweeted that the state's "thoughts and prayers go out to the Ohio State community. Be safe, listen to first responders."
President Barack Obama was briefed on the attack, a White House spokesman said. The FBI was assisting in the investigation.
Hassan Omar, president of the Somali Community Association of Ohio, told NBC News that reports the attacker was Somali was upsetting.
"Every Somali person has been calling me, and everybody is crying," he said.
"This is a shock," he added. "As a Somali community here, we are in a state of shock. In Columbus, we live in a very peaceful community. This is gonna affect the life of everybody. We are American and we don't want somebody to create this problem."