Police locked down several UA buildings Friday evening after a report of a man on campus with a gun.
An extensive search was conducted but no sign of a gunman was found.
"No shots were heard and no unusual activity was seen," said Officer Jose Bermudez of the UA Police Department.
No injuries were reported in the three-hour incident, but dozens of law enforcement officers converged on the campus, where in October 2002 a failing student shot and killed three professors in the College of Nursing before killing himself.
A call came in to 911 at 4:52 Friday reporting a man on campus "carrying a rifle and with a gun strapped to his chest," Bermudez said. The caller also said a shooting had occurred in the Administration Building and asked where the police were.
A campuswide text alert went out at 5:06 p.m. telling recipients about the police incident and to stay away from the building, which is in the middle of the campus. Several text alerts were sent out during the incident, updating the campus about what was happening.
University of Arizona and Tucson police officers surrounded the Administration Building and officers were stationed outside nearby buildings. Numerous streets were closed to traffic. About 20 Tucson police cars could be seen on campus.
At about 6 p.m., officers went into the Administration Building and began searching and escorting out those found inside. The Modern Languages Building next door was also evacuated as a precaution.
State Rep. Ethan Orr, R-Tucson, said he was in the Administration Building when the text alert went out. He said a group of people remained in the building for about an hour until being escorted out by police. He said the evacuation was orderly.
"I thought about my wife and children," Orr said.
Officers searched the seven-floor building room by room, Bermudez said. The search was completed shortly after 8 p.m. and police reopened the campus buildings.
Bermudez said he couldn't comment on whether any UA administrators were in the Administration Building when the lockdown began.
Economics student Rachel McCluskey, 20, said the incident was unsettling.
"I think it's pretty bizarre. It doesn't happen every day," she said.
UA employees, students and curious passers-by milled around at the nearby Student Union waiting for more news.
Several Papa John's employees clustered behind a wall just west of Second Street, where Kaitlyn Brunet and Cody Baron said police had told them to stand, out of a possible line of fire.
Student Union assistant director Nick Adamakis gazed at the line of squad cars blocking Second Street. Adamakis said he has been with the UA about 15 years and remembers the shooting at the nursing school in 2002.
"You wonder," he said, shaking his head. "You speculate. ... I'm wishful it's just a hoax."
"You wonder, you speculate. ... I'm wishful it's just a hoax."
Nick Adamakis, Student Union assistant director
Did you know?
In 2007, the University of Arizona launched an emergency alert system that allows students, employees, family members and others to receive text messages if a crisis occurs on or near the campus.
Star staffer Hannah Gaber contributed to this report. Contact reporter Joseph Treviño at 807-8029 or at email@example.com