A 15-year-old student was stabbed to death Friday morning in the hallway of a high school in this affluent Boston suburb, and a classmate was charged with the killing.

James Alenson was stabbed in a fight with another male student before classes began at Lincoln-Sudbury Regional High School, District Attorney Gerard Leone said. The fight began in a bathroom and spilled into the hallway, Leone said.

Alenson, a freshman, was pronounced dead at a Concord hospital.

The 16-year-old suspect, who was identified in court papers as John Odgren, of Princeton, was to be arraigned as an adult on a murder charge Friday afternoon, Leone's office said. In first- and second-degree murder cases in Massachusetts, anyone age 14 or older is automatically tried as an adult.

Leone, who would not comment on a possible motive, called the fight an "isolated incident" between the two students. "There is no thought or belief that anyone else is in danger," he said.

Mary Clemens, a 17-year-old senior, said that when she arrived at the campus, students had gathered in the cafeteria.

"We were told by an administrator that someone was stabbed and it was bad, that that person was taken to the hospital and someone else had been taken to the police," Clemens said.

Students were sent home that morning.

"We're obviously heartbroken dealing with this," said John Ritchie, the school's superintendent and principal.

About 1,600 students attend the school, which is about 17 miles west of Boston.