An early-morning explosion in Allentown on Sunday left 10 homes uninhabitable and displaced nearly four dozen people as a resulting fire tore through a residential neighborhood.

Officials were working to determine the cause of the blast, according to the Allentown Morning Call.

“It’s a real mess here right now,” fire Capt. John Christopher told the newspaper Sunday morning.

According to the Associated Press, one person was taken to a hospital for a minor injury and a firefighter was treated for a shoulder injury. One person initially unaccounted for was later found safe.

Neighbors said they were awakened by a deafening explosion about 3 a.m. that appeared to have erupted from a home on the 700 block of North Fountain Street. Fire ripped through adjacent houses.

Responding emergency workers said they did not detect the scent of natural gas.

The Red Cross of Eastern Pennsylvania said Monday morning it was assisting 47 people from 13 families displaced by the explosion and fire.