A Brookwood High School senior has been arrested for allegedly starting a fire that destroyed one classroom trailer and significantly damaged another trailer at the school.

Matthew Cooper, 17, of Snellville, turned himself in to Gwinnett authorities on Wednesday, said Gwinnett fire department spokesman Capt. Thomas Rutledge. He has been charged with first-degree arson and second-degree criminal damage to property, both felonies.

Rutledge said the teenager admitted setting the fire when he was questioned by investigators.

A coach and several members of the Brookwood cross country team saw smoke coming from behind the school around 6:47 a.m. Aug. 16 — a Saturday when school was not in session. By the time firefighters arrived, the blaze had engulfed one trailer and was spreading to a second trailer. Fire crews extinguished the blaze before it threatened the main school building, Rutledge said.