A Northern California high school remains closed a day after a 17-year-old boy armed with a chain saw, sword and explosives detonated two pipe bombs.
The explosions Monday morning at Hillsdale High School in San Mateo didn't cause injuries or serious damage, but the 1,270-student school was evacuated and remained a crime scene Tuesday.
Police arrested the boy after a teacher tackled him. The teen was wearing a vest laden with pipe bombs.
Police identified him as a former student but won't release his name because he is a minor.
Authorities have not discussed a possible motive for the attack.
Detectives are preparing search warrant affidavits for the boy's home, and prosecutors are deciding whether to charge him as an adult.