PHOENIX — The body of a man who apparently tried to break into an elementary school was discovered Friday in an air conditioning duct on the school’s roof, police said.

The body at Sierra Vista Elementary School was found as a plumber investigated a foul odor noticed by cafeteria staff earlier in the day, said Roosevelt School District Superintendent Mark Dowling. The school was evacuated.

Authorities think the man tried to climb through the duct, got stuck, and died. It wasn’t known how long the body was there.

“Obviously because of the smell, there are indications that he had been there for some time,” said Sgt. Andy Hill, a Phoenix police spokesman.

The man’s name wasn’t released.

Dowling said the children were scheduled to be dismissed early Friday and that some parents were already on their way when the school began notifying them about the body. The school has about 550 students in preschool through eighth grade.

David Torres, who arrived at the school midday to pick up his two sons, said he was surprised to see police and TV helicopters when he arrived.

“I was thinking something real bad had happened,” said Torres, who was leaving with his boys. “I got nervous and I started to look for my kids.”

A psychologist will be at the school when it reopens Tuesday, Dowling said.