LONDON (AP) — An explosion and fire in an apartment building on the Channel Island of Jersey killed one person and left several missing Saturday, police said.

Robin Smith, the chief officer of the States of Jersey Police, said during a news conference that “around a dozen” residents were missing following the blast in the town of St Helier.

Jersey, the largest of the Channel Islands, is a self-governing dependency of the United Kingdom located off the coast of northern France in the English Channel.

Smith said a three-story building had “completely collapsed” and there was also damage to a nearby building. He described the scene as “devastating” and warned there could be more fatalities.

Smith said the fire service had been called to the area the night before after residents reported smelling gas.

He said police would investigate “whether or not there was a safety issue” with natural gas lines.

Police said in a statement that while the fire was extinguished, emergency service agencies were carrying out significant work” at the scene.

Authorities advised Jersey residents to only seek emergency hospital care in the event of an actual medical emergency and to avoid the area of the blast, which was cordoned off.