The fire that destroyed part of the Riverhead Charter School was caused by an electrical problem in the school's heating and air conditioning unit, the Riverhead fire marshal said Friday.
Chief Fire Marshal Scott Davonski said the unit was mounted externally with duct work running into the ceiling of the prefabricated building, which housed some of the Calverton school's K-3 classes.
The heating, ventilating and air conditioning unit was regularly maintained, according to the school's records, Davonski said. He said there was no fault, and the investigation was concluded.
Principal Dorothy Porteus said the school community's primary focus has been finding a new home together for the rest of the year, not the cause of the fire.
The K-6 school will use St. John's School at 546 St. John's Place in Riverhead for the rest of the year, she said.
"We've been more concerned about getting our kids into a building and back into school," Porteus said Friday. "Once things are settled down here and we get into a routine, we'll be talking about it."