YORK – The state Fire Marshal’s Office will investigate the fire that destroyed a historic oceanfront mansion, York Village’s deputy fire chief said.

Fire officials have not yet determined what caused the fire in the oceanfront house, York Village Deputy Fire Chief David Apgar said. The Fire Marshal’s Office will be contacted to help investigate, partly because of the house’s value.

The 1929 mansion, assessed at $1.2 million, was designed by American architect John Russell Pope, who is best known for designing the National Gallery of Art in Washington, D.C.

Apgar said that while he is not a building expert, he doesn’t think the house can be rebuilt.

Sixty firefighters from 10 departments fought to contain the blaze, which began around 12:30 p.m. Wednesday and took firefighters more than four hours to extinguish. Flames were still visible around the roof at about 4 p.m.

Apgar said the fire was difficult to fight because it had “a good head start” before firefighters arrived on the scene. Wind from the ocean fanned flames through the house and the hydrant across the street could pump water for only one hose at a time. Firefighters ran 1,500 feet of hose to York Street for more water.

“It was brutal,” said Ogunquit Fire Chief Doug Patey, whose department helped with the cleanup. He said firefighters had to use sledgehammers and other heavy tools to quell the flames.

Firefighters had to evacuate the home several times when parts of the roof and one of the chimneys collapsed.

Officials identified the owners of the house at 15 Milbury Lane as the Peterson family of Virginia. The house was vacant for the winter and was overseen by a caretaker living in a cottage next to the main house.

York Harbor resident Helen Rollins said the house, which stood at the end of the Cliff Walk, was a landmark for sailors.

“Once you saw the big white house, you knew you were there,” she said. “It’s a glorious house.”