Investigators are searching for a motive behind an Ohio State University student's knife attack on campus Monday morning that wounded 11 people.
Abdul Razak Ali Artan, a student who recently transferred there, had written in a Facebook post he had grown "sick and tired" of seeing fellow Muslims "killed and tortured," according to federal law enforcement officials. Authorities are now looking into whether the attack was terrorism but said it would take time to determine a motive.
In a Facebook post shortly before the rampage, the Somali immigrant urged America "to stop interfering with other countries, especially the Muslim Ummah," a term for Muslim people at large.
"By Allah, we will not let you sleep unless you give peace to the Muslims," he wrote. "You will not celebrate or enjoy any holiday."
Artan rammed his car into a group of people on the Columbus campus. He then exited the car and charged at passersby with a knife.
Ohio State Police Officer Alan Horujko shot Artan after he failed to obey orders to stop -- ending his life and stopping the tragic attack.
What we know about the attacker
Back in August, Ohio State's student-run newspaper profiled Artan as part of its "Humans of Ohio State" series. He had just transferred from Columbus State and expressed his struggles to find a place to pray in peace on the large campus.
"I wanted to pray in the open, but I was scared with everything going on in the media," he told the paper.
Artan, who was originally from Somalia, left his native country with his family in 2007. They headed to Pakistan, where they were admitted as refugees as part of a minority sect of Somalis, a senior administration official told CNN. Seven members of the family applied for refugee status in the United States and were admitted in 2014. Today, they are all legal permanent residents and green card holders.
A community member, who described Artan as a good kid, said the attacker's family sounded shocked during a conversation.
Neighbor Stephanie Leper told CNN that Artan's family lives in four town home units. Law enforcement vehicles arrived there sometime after 10 a.m. and took people away in "paddy wagons," she said.
Artan said reports of human rights abuses in Myanmar pushed him to a "boiling point." The United States, which suspended its last sanctions against the former military dictatorship this year, said it had expressed concerns about the treatment of Myanmar's Rohingya Muslims.
"I can't take it anymore," he said in the post.
Three calls, three shots, one dead
At 9:52 a.m. Monday, Artan drove over a curb and struck people near Watts Hall.
Jacob Bower, a 20-year-old student, 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 told CNN, adding that he did not see anyone get stabbed.
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," the student said.
Artan's rampage ended in less than two minutes thanks to Officer Horujko's quick response, officials said.
Horujko called in the car at 9:52 a.m. A few seconds later, he called again to say he had engaged with the suspect. At 9:53 a.m., he called a third time to say he had shot the suspect.
It took Horujko three shots to kill Artan, Bower said.
"The cop that subdued the guy with the knife saved so many lives today."
Investigators used surveillance camera footage to track Artan's car before he arrived on campus, University Police Chief Craig Stone said. By tracing his movements, investigators were able to conclude he was alone in the vehicle and acted alone.
Gov. John Kasich praised the response, saying it showed "how much practice, how much training, how much expertise, how much coordination" existed among local law enforcement agencies.
"We are a strong, tough, resilient community," he said.
'Run, hide, fight'
Ohio State President Dr. Michael V. Drake and others credited the school's active shooter training and the campus alert system for helping the community maintain order while the scene was secured. Ohio State's Columbus campus is one of the largest in the United States. Nearly 60,000 registered students attend classes on the sprawling urban campus.
At 9:55 a.m., three minutes after Horujko's first call, the school sent out a campus alert reporting an active shooter incident.
"Buckeye Alert: Active Shooter on campus. Run Hide Fight. Watts Hall. 19th and College," Ohio State Emergency Management tweeted at 9:56 a.m.
Some students piled chairs against a door to block him from getting in as they awaited word on the attacker's movements.
In 911 calls to police, several students described the chaotic scene.
"I think this is some type of terrorist attack," said one caller, according to CNN affiliate WCMH. "Because the guy ran a car through a crowd of students. The guy did it purposefully."
About 90 minutes after the first call came in, the lockdown was lifted, Drake said.
Students had just returned to class Monday after Thanksgiving break -- and after the OSU football team's big win Saturday over the school's biggest rival, the University of Michigan.
Overall, it was "one of those days you're grateful for good training and great people across the board," Columbus Mayor Andrew Ginther said.
OSU officials uncertain if attack was terrorism
In a news conference Monday, Drake cautioned against jumping to conclusions when asked if the incident was terror-related or had anything to do with Ohio's Somali community, the second-largest in the country.
"We certainly don't have any evidence that would say that's the case," Drake said.
"What we want to do is really unify together and support each other; do our best to support those who were injured in their recovery, and then allow the investigation to take place."