BROOMFIELD, Colo. — It was a somber start to homecoming week Monday at a suburban Denver high school after a bus carrying junior varsity football players and staffers crashed at the airport, killing the driver and injuring 18 passengers, some critically.

The bus veered off a roadway and slammed into a concrete pillar Sunday afternoon at Denver International Airport after picking up members of the Legacy High School football squad. The students were returning from a football game in California, and the vehicle was circling back to the airport when it crashed.

“Everybody is just kind of in shock,” senior Emily Stockhus said Monday before classes at the school in Broomfield, north of Denver. A crisis team was there to help students.

Neither the cause of the crash nor the name of the female driver was released. The bus carried 28 students and four adults, airport spokeswoman Heath Montgomery said.

Fifteen students and three staff members were injured, sending 10 to hospitals, officials said. The others were treated and released.

Two victims at Denver Health Medical Center were in critical condition, two in serious condition and one in fair condition.

School officials told The Denver Post that some of this week’s homecoming events were being postponed, including a game planned for Monday evening.

Students are trying to use homecoming week “to work together as a team, school to build a really strong team together,” Stockhus said.

The Legacy High team had played a game Friday against Chino Hills High School in suburban Los Angeles.