WOODBURN, Ore. – Three 15-year-old Oregon boys accused of setting a fire that destroyed part of Woodburn High School on Friday have been arrested, police said.

The trio, all students at the school, were arrested for investigation of first-degree arson, reckless burning and reckless endangering, police Sgt. Nick Wilson said Friday night.

Students and staff members evacuated the 1,400-student high school Friday morning as fire crews responded. No one was injured.

The fire burned through the school’s wood and metal shops.

The high school will be closed this week to assess damage, school district spokeswoman Margarita Roberts said in a statement Friday. The district is working to find alternate locations for classes, she said.

As many as 60 firefighters from a dozen agencies fought the blaze, said Lt. Darin Unrein of the Woodburn Fire District.

The three boys were taken to the Marion County Juvenile Detention Center after police interviews, Wilson said.

“They did provide us with an account of what happened,” he said, declining to discuss a motive or precise cause for the fire. He said the investigation was continuing.

“We went out like it was a planned fire drill, but when we were told to go to the football field we knew it was real,” Rico Lopez, a junior, told the Salem Statesman Journal of the evacuation. “We’d never done that before.”

Students streamed from classrooms to the bleachers at the football field. From there, they were bused to a nearby medical clinic, where parents picked them up.

The fire was reported shortly before 9:30 a.m. Friday and was under control by noon.

Woodburn is situated along Interstate 5 midway between Portland and Salem.