A natural gas explosion at a school in the US has killed two people and left the building partially collapsed.
Federal authorities have joined an investigation into the explosion, which sent students, some as young as five-years-old, fleeing as the building began to collapse.
All students at the Minnehaha Academy school in Minnesota were accounted for following the blast.
Two people were killed in the explosion, the school’s janitor and receptionist. Nine other people were injured.
Three remain in hospital, with one in a critical condition according to the Hennepin County Medical Center.
The school said in a statement: "This morning our prayers are with Minnehaha's facilities team member Bryan Duffey and his family. We pray for his healing and for the wisdom of the doctors and nurses caring for him at this time."
The National Transportation Safety Board, known for investigating plane and train crashes, has sent an investigative team to the school.
The explosion happened yesterday morning in one of the school campus buildings where a construction crew had been working.
The blast pushed part of the building's wall outwards causing the roof to collapse, according to fire chief John Fruetel.
