When firefighters arrived at Tomeo Farms feed and hardware store in Mercer at about 2:30 a.m. Monday, fire had already enveloped the 10,000-square-foot building.

“Everything was already destroyed when we were called,” said East End Volunteer Fire Chief Bill Finley Jr. “When the first truck came in the roof was already collapsing.”

The feed store, at 659 E. Market St., was leveled by the fire, except for some charred posts that remained upright and part of the wooden front stoop.

A demolition crew used an excavator to overturn rubble as firefighters hosed down hot spots later Monday morning. Stored hay and straw still smoldered at around noon.

There was no way to douse the fire in the large old building when firefighters arrived, Finley said. Fire hydrants couldn’t provide enough water to put out the blaze, he said.

Instead, firefighters focused on keeping it from spreading to nearby buildings, including an office building for Reznor’s, a unit of Thomas & Betts Corp., which stood untouched and directly behind the burned ruins of Tomeo’s.

“We put a lot of water on the buildings to slow the progress,” Finley said.

One Jackson Center firefighter was injured when he slipped on some ice, Finley said. He was treated at Grove City Medical Center, Pine Township.

The Tomeo family who owned the business were insured, Finley said. Messages left for them on Monday afternoon were not returned.

There was also a power outage caused when the fire took part of a grid down, he said. At the scene, a phone cable had drooped nearly low enough to touch.

A message left for the state police fire marshal was not returned. Finley said as of Monday afternoon there was no word on cause, but the fire marshal had an idea of where the fire started.

East End was assisted by Pine Township Engine Co., and Jefferson, Jackson Center, Sandy Lake, Fredonia, Springfield and Grove City volunteer fire departments.