An explosion at the Warwick, R.I., Public Works Department destroyed three trash trucks and caused a fire, Mayor Scott Avedisian said. Firefighters extinguished the blaze and no one was injured, The Providence Journal reported. The trucks were last used Saturday afternoon and were mostly empty when the explosion occurred about 9 p.m. EDT Saturday, Avedisian said. The state fire marshal\'s office has begun investigating the explosion and checking security videos, the Journal said.