AUSTIN, Texas – A student wearing a dark suit and a ski mask opened fire Tuesday with an assault rifle on the University of Texas campus before fleeing into a library and fatally shooting himself. No one else was hurt.

The shooting began near a fountain in front of the UT Tower – the site of one of the nation’s deadliest shooting rampages more than four decades ago, when a gunman ascended the clock tower and fired down on dozens of people.

Within hours of Tuesday’s gunfire, the school issued an all-clear notice, but the university remained closed, and the area near the library was still considered a crime scene.

“Our campus is safe,” school President Bill Powers said.

Austin Police Chief Art Acevedo expected the school to be “completely open and back to normal” by Wednesday morning.

Authorities identified the gunman as 19-year-old Colton Tooley, a sophomore math major. Police declined to speculate on his motive. Tooley’s parents did not immediately respond to a message left by The Associated Press.

At his family’s home in Austin, police investigators went in and out Tuesday afternoon carrying bags and boxes. There was no immediate word on what was in the containers. A neighbor said police arrived at the home about three hours after the campus shooting.

The 50,000-student university had been on lockdown while officers with bomb-sniffing dogs carried out a building-by-building manhunt.

After the gunfire, authorities searched for a possible second shooter, but they eventually concluded the gunman acted alone. Confusion about the number of suspects arose because shots were fired in multiple locations, and officers received varying description from witnesses, said campus police Chief Robert Dahlstrom.

Before reaching the library, the gunman apparently walked for several blocks wearing a mask and dark clothing and carrying an automatic weapon, witnesses said. Construction worker Ruben Cordoba said he was installing a fence on the roof of a three-story building near the library when he looked down and made eye contact with the suspect.

“I saw in his eyes he didn’t care,” Cordoba said.

The gunman continued down the street, firing three shots toward a campus church, then changed direction and fired three more times into the air, Cordoba said.

A garbage truck driver leaped out of his vehicle and ran away, as did a woman carrying two babies, the construction worker said.

“I’m not scared, but I was scared for the people around me,” Cordoba said.

Randall Wilhite, an adjunct law professor, said he was driving to class when he saw “students start scrambling behind wastebaskets, trees and monuments,” and then a young man carrying an assault rifle sprinting along the street.

“He was running right in front of me … and he shot what I thought were three more shots … not at me. In my direction, but not at me,” Wilhite said.

The professor said the gunman had the opportunity to shoot several people, but he did not.

Police said it was unclear whether the gunman was targeting anyone with the AK-47.

Oscar Trevino, whose daughter works on campus, said she told him she was walking to work near the library when she heard two shots behind her. She started to run and fell down. She said she later heard another shot.

“She’s freaking out. I’m trying to calm her down. I’ve just been telling her I love her and relax, everything’s fine,” Trevino said.

Acevedo said officers were able to track the gunman’s movements with the help of students who “kept pointing in the right direction.”

The police chief said he believes the gunman ran into the library as officers closed in on him, then shot himself in the head.