Three firefighters and two civilians were injured on Wednesday after a natural gas leak caused an explosion at a bagel shop in Portland, Oregon, Portland Fire & Rescue said.

The explosion, which destroyed the Portland Bagelworks restaurant, triggered a four alarm fire that sent a large plume of black smoke into the air.

No fatalities were reported from the blast. Those in the immediate vicinity of the fire were asked to shelter in place.

The incident began when a contractor hit a gas line, prompting an evacuation of the building. When crews started to respond the leaking gas ignited, causing the explosion, according to Fox 12 in Portland.

It is unclear what ignited the blast.

Portland Fire & Rescue said structural engineers were called in to investigate.