CARLISLE, Pa. — A road trip by a college women’s lacrosse team came to a horrifying end Saturday when the team bus veered off the Pennsylvania Turnpike and crashed into a tree, killing a pregnant coach, her unborn child and the driver, and injuring numerous others, authorities said.

Seton Hill University team players and coaches were among the 23 people aboard when the bus crashed just before 9 a.m. No other vehicle was involved, and police could not immediately say what caused the accident.

Coach Kristina Quigley, 30, of Greensburg was flown to a hospital but died there of injuries she suffered in the crash, Cumberland County authorities said. Quigley was about six months pregnant and her unborn child did not survive, authorities said. The bus driver, Anthony Guaetta, 61, of Johnstown, died at the scene.

The other passengers were removed from the bus within an hour and taken to hospitals as a precaution. The crash appeared to have shorn away the front left side of the bus, which rested upright about 70 yards from the road at the bottom of a grassy slope.

The lacrosse team was headed to play Saturday afternoon at Millersville University, about 50 miles from the crash site in central Pennsylvania, for its fourth game of the year.

Both Saturday’s game and a Sunday home game were canceled after the crash, and Seton Hill, a Catholic school of about 2,500 students near Pittsburgh, said a memorial Mass was planned for Sunday night on campus.

Duquesne University women’s lacrosse coach Mike Scerbo remembered Quigley as a warm, outgoing person who immediately impressed him when he hired her to be an assistant during the 2008 season.

Quigley, also a Duquesne alum, spent just one season under Scerbo before moving to South Carolina to start Erskine College’s NCAA Division II program.

“In that time, I really saw how much passion she had to be a coach, and how much she enjoyed working with the kids,” Scerbo said. “She was a teacher, and she wanted to help kids grow and learn, not just about the sport, but about life.”

She spent three years at Erskine before taking the top job at Seton Hill for the 2012 season. She stayed in touch with Scerbo, often seeking his guidance and showing up at the Duquesne alumni game.

“She was a very happy person, very passionate about life, about her players, about her job and most importantly about her family,” Scerbo said.

The bus operator, Mlaker Charter & Tours, of Davidsville, Pa., is up to date on its inspections, which include bus and driver safety checks, said Jennifer Kocher, a spokeswoman for the state Public Utility Commission.

On Tuesday, another bus carrying college lacrosse players from a Vermont team was hit by a sports car that spun out of control on a wet highway in upstate New York, sending the bus toppling onto its side, police said. One person in the car died.

In February, a bus carrying the University of Maine women’s basketball team crashed on Interstate 95 north of Boston. Despite a scene described as terrifying by witnesses, players and coaches walked away with minor injuries.

Also last month, a bus carrying 42 high school students from the Philadelphia area and their chaperones slammed into an overpass in Boston, injuring 35. Authorities said the driver had directed the bus onto a road with a height limit.