FARGO, N.D. (AP) — Thousands of students and staff at North Dakota State University poured off campus Friday in a stiff test of the school’s emergency system, after a bomb threat came in about the same time as a similar threat prompted an evacuation at the University of Texas.

Authorities said they didn’t know if the two threats were related, but both schools gave the all-clear just a few hours into the evacuations.

In North Dakota, school officials and police said the rare full evacuation went smoothly even as traffic became thick and some streets were blocked. The school has 14,500 students.

Many students evacuated by crossing just off campus, including hundreds who flooded the Bison Turf, a popular hangout known for cheap eats and drinks.

“It was chaos,” bartender Lucas Jens said. “There were cars and kids everywhere. Thirsty and hungry kids. Nervous kids.”

Police said no accidents were reported, and one campus employee said people were “being North Dakota nice” as they drove away.

“The line of cars to get off campus was pretty long,” said that employee, Juleen Berg, who works at the heating plant. “It was very orderly. Nobody was panicked, and nobody was trying to speed or run over anybody. Everybody was waiting their turn.”

North Dakota State got a call about 9:45 a.m. that included a “threat of an explosive device,” FBI spokesman Kyle Loven said. That was a little more than an hour after a similar threat was made in Austin, Texas.

Lee Kiedrowski, a 26-year-old graduate student from Dickinson, N.D., said he was walking to a class building just before 10 a.m. when he got a text message telling him students had been ordered to evacuate by 10:15.

Students were notified of the evacuation by email and automated phone calls. Messages also went out via social media, such as Facebook.

Cars were soon streaming off the campus as thousands of people tried to leave the area. Kiedrowski saw squad cars at major intersections.

“The panic button wasn’t triggered quite immediately,” said Kiedrowski, who is studying infectious disease management and biosecurity. “But there was definitely the thought that we live in a different world now, and with everything that’s going on with the riots at the U.S. embassies in the Middle East, your brain just starts moving.”

Thomas Brown, of Sartell, Minn., president of the Sigma Alpha Epsilon fraternity, said students weren’t told where to go but just to “walk to locations off campus.” Since his fraternity house is off campus, he and other members went there.

Brown said he was scared by the thought that there might be a connection between the NDSU and Texas threats.

“It’s crazy to think that it is happening on opposite ends of the country,” he said. “North Dakota is a very safe state. There are a lot of nice people. To have something happen along these lines is a little sad.”

Loven wouldn’t give more details on the call, nor would Fargo police or university President Dean Bresciani. The president stopped short of saying nothing was found during a campus search, saying only that it was “deemed safe” before the university reopened at 1 p.m.

Bresciani said the downtown and main campuses were evacuated, along with the school’s agricultural facilities. While classes officially resumed at 2 p.m., many professors cancelled them and afternoon activity at both the main and downtown campuses was sparse.

“I came back to go to class, and it was cancelled. I didn’t check that,” said Zach Johnson, a marketing major who was one of the few students at NDSU’s Barry Hall late in the afternoon. “I was a little concerned because this is my campus. There’s a lot of stuff going on in the world today … and it’s just nuts that this is North Dakota.”

Fargo police Lt. Joel Vettel said the evacuation took a little less than 90 minutes.