EAGAR, Ariz. -- Federal investigators on Sunday began looking through smoldering wreckage for clues to what may have caused a small plane to nosedive into an Arizona high school and explode Friday afternoon.
Apache County sheriff's Sgt. Richard Guinn said firefighters were able to extinguish the last of the hot spots Saturday so authorities could recover the bodies of four people who were aboard the single-engine Piper when it crashed into the empty two-story school building in the small town of Eagar.
Guinn said authorities have not been able to identify the bodies or determine even the gender or age of the four people.
Officials with the Federal Aviation Administration and National Transportation Safety Board planned a briefing in front of the school Sunday afternoon.
There is no indication yet of what caused the crash. Guinn said investigators are examining flight plans and weather conditions at the time of the crash and will look at the plane's control systems as they comb through the wreckage.
"They're working on recovering all of the wreckage, documenting where all the pieces are and the debris path," he said.
The plane circled the area two or three times before it suddenly crashed into the main building at Round Valley High School at about 2 p.m. Friday. Hours after the crash, flames were still erupting above the building.
Fire crews from nearly a dozen small towns in the region raced to battle the flames. Officials evacuated homes in neighborhoods east and north of the school.
There were no reports of injuries on the ground. Classes at the school are out for the summer, and Guinn said no teachers or staff were on the grounds because they work a four-day week during the break.
The school serves about 500 students in Eagar and nearby Springerville and is about 200 miles east of Phoenix. The blaze was contained to the main school building.