Four people were killed when a Dallas Cowboys tour bus carrying staffers but no players and a van were involved in an accident just outside Dolan Springs in northwest Arizona on Sunday afternoon, officials said.

The accident occurred on Highway 93 northbound, the main route between Phoenix and Las Vegas, and caused a shutdown of a northbound lane, according to the Arizona Department of Public Safety.

The fatalities were passengers in the van, DPS spokesman Quentin Mehr said. A spokesman for the Cowboys said neither the bus driver nor any passengers were seriously injured.

“All on the bus came through OK with some bumps and bruises,” Cowboys senior vice president of public relations and communications Rich Dalrymple said in an email.

Dalrymple said the bus was only carrying members of the franchise’s staff but did not say how many. There were no players on board.

The bus was on its way to a Gameworks restaurant in Las Vegas, where organization members were to meet fans and sign autographs as part of a multi-state tour, according to a report on the team’s website.

The bus was scheduled to visit the Salty Señorita in Peoria, Ariz., on Saturday after making a stop in Tucson as a part of their “Road Trippin’ 2016″ tour. The team left Sunday morning for Las Vegas, according to Mickey Spagnola, a columnist who is traveling with the tour.

The tour provided fans with opportunities for meet-and-greet sessions and a chance to get autographs from members of the Cowboys organization. The final scheduled stop of the tour was slated for Monday at a Los Angeles steakhouse.

Carlos Montoya, a manager at Gameworks in Las Vegas, said the bus was scheduled to arrive at the entertainment-themed restaurant at 3 p.m. PDT

“There was a crash and it made them unable to come,” Montoya said.

Another manager, Charles Cooper, told the Associated Press that fans were already waiting when the president of a Las Vegas Cowboys fan club called to relay news of the accident. The event was subsequently canceled. Cooper says the team mascot was supposed to appear.

Contributing: The Arizona Republic, part of the USA TODAY Network, and the Associated Press.