A caretaker has been airlifted to hospital and a Buckinghamshire school evacuated following an explosion and fire at his house within the grounds.
Emergency services were called to John Hampden Grammar School in High Wycombe at about 1400 GMT on Thursday.
The caretaker is believed to be suffering from burns, the county council said.
There were no other injuries, and students were taken out of the school buildings as a precaution.
The A404 was closed to traffic between Handy Cross roundabout and the A40 for just over an hour.
Buckinghamshire Fire and Rescue Service said firefighters are still at the scene and the two-storey house has been severely damaged by fire.
A man had been rescued from the house before they arrived and had been taken to hospital by air ambulance.
Thames Valley Police and South Central Ambulance Service are also in attendance.