Officials say they're still not sure what sparked a fire at Easton Area High School, but they have ruled it an accident.
The fire broke out last Friday morning in the wood shop at the school, located at 2601 William Penn Hwy. in Palmer Twp.
No one was hurt, but students and teachers were briefly evacuated.
On Wednesday, the fire chief ruled the fire accidental and the cause "undetermined".
He says a spark in the wood shop area ignited fumes in an exhaust fan, but officials aren't certain what caused the spark.
The chief says the fire would have been smaller if the exhaust fan hood had been properly cleaned and maintained.