Cadaver dogs are searching the smoldering remains of a Kansas City restaurant that burned to the ground following a gas explosion and massive blaze, a fire official says.

Kansas City Fire Chief Paul Berardi said late Tuesday that the search for possible victims could take hours and that he expected his crews to be at the scene through the night.

While officials have said they have no reports of fatalities, Berardi noted, “I would always fear there are fatalities in a scene like this.”

The gas explosion occurred just after 6 p.m. and the resulting fire completely destroyed JJ’s restaurant. Officials say more than a dozen people were injured, with at least two reported in critical condition.

The cause of the blast remains under investigation; however, a city official earlier said it was believed to have been caused accidentally by a utility contractor.