Investigators continued on Friday to comb through the wreckage of a bus that went off a New York highway and overturned while carrying a Long Island high school marching band to Pennsylvania the day before, killing two people and injuring dozens of others.

Although Gov. Kathy Hochul said on Thursday that a faulty front tire appeared to have caused the bus to veer off the road, investigators from the National Transportation Safety Board, the New York State Police and the Orange County, N.Y., Sheriff’s Office were seeking to determine whether other factors may have been involved, officials said. A safety board briefing was scheduled for Friday afternoon.

As the inquiry proceeded, officials said that one of the two people killed in the crash, Gina Pellettiere, had suffered injuries to her head and torso when the bus tumbled down a 50-foot ravine on a stretch of Interstate 84 in the town of Wawayanda. The second person killed in the crash, Beatrice Ferrari, died while being taken to a hospital, officials said.

Ms. Pellettiere, 43, and Ms. Ferrari, 77, were among four adults and 40 students from Farmingdale High School who were on one of six coach buses taking the marching band on its annual trip to a camp in Pennsylvania. Ms. Pellettiere was the band’s beloved director; Ms. Ferrari was a volunteer chaperone.

Naomi Luke, 14, a freshman at Farmingdale High School, was FaceTiming with her best friend, who was on the bus with her bandmates, when she heard the screech of tires.

The image on Naomi’s phone spun, her mother, Carolina, said in an interview. When her friend’s face reappeared on the screen, it was covered with blood. The girl had a broken nose and cuts on her tongue and lips, Ms. Luke said.

In addition to the two deaths, at least five people, including several students, were critically injured. One, a freshman, was released to his parents on Friday morning after getting stitches and staples in his head and body, Ralph Ekstrand, Farmingdale’s mayor, said.

Another freshman, a girl whose spine was fractured, was taken from Westchester Medical Center to Cohen Children’s Medical Center in New Hyde Park on Long Island, Mr. Ekstrand said. Nearly 20 other people, most of them students, were still being treated at other hospitals, officials said.

Ms. Pellettiere was known for her sense of style and love of music, said Ms. Luke, who had been her classmate at Hicksville High School. She played “every instrument,” said Ms. Luke, who described spending Friday morning looking at Ms. Pellettiere’s picture in the high school yearbook. “She was the light of the classroom.”

Classes were in session at the high school on Friday, but a football game scheduled for the evening was canceled, as were other after-school competitions that had been planned for the weekend.

Bruce Blakeman, the Nassau County executive, said at a news briefing that counselors would be available through at least next week for anyone who might need their services.

Rose Walker, a Nassau County legislator whose district includes Farmingdale, said at the briefing that the crash was “personal” for her.

“I know many of these children, the staff,” Ms. Walker said. “I always tell them when we’re at anything together that although they don’t live in my house, they’re all my kids.”

Ms. Walker said that she had known Ms. Pellettiere, the band director, since Ms. Pellettiere was in grade school. Ms. Pellettiere “had a love for music,” Ms. Walker said, and was a drum major in high school.

“It was a dream to go further with her career, and she did, she became that band director over at Farmingdale High School,” Ms. Walker said.

Sarah Maslin Nir and Ellen Yan contributed reporting. Kirsten Noyes contributed research.