HOMERVILLE, Ga. (AP) -- Authorities say natural gas leaking into a sewer line caused an explosion that destroyed a coffee shop in rural Georgia and seriously injured three people.

Glenn Allen, a spokesman for Georgia Insurance and Safety Fire Commissioner Ralph Hudgens, said late Friday that investigators determined a construction crew installing fiber optic cable in the tiny city of Homerville punctured an underground natural gas line.

Explosion at Homerville coffee shop sends 3 employees to the hospital

Allen says that gas leaked into a sewer line connected to the coffee shop, where the gas built up and was ignited by a spark shortly after noon Friday.

Allen says two employees and a customer suffered serious injuries, including burns. Investigators initially reported all three injured people were coffee shop employees.

The injured people were airlifted to a hospital in Gainesville, Florida.