An explosion destroyed the home of a Lancaster General Hospital doctor Thursday morning, leaving only a chimney with a cross on it standing.

Dr. Jonathan Gish, his wife, Karen, and their children, ages 21, 19 and 15, weren't home at the time.

"We had a fireplace and my husband put a cross at the top of that. And that's the only thing left standing of the house. ... And it's perfect because that's the most important thing to all of us, is our faith," Karen Gish told the York Daily Record.

"All of us were out of the house. And that in itself is just a miracle," she told the paper. The family's German shepherd, Briere, was outside and was hit with debris and taken to a veterinarian.

Lower Windsor Township Police Chief Tim Caldwell said anyone home "would have been dead. There's no doubt about it."

The explosion at 150 Calvary Church Road was reported shortly before 5 a.m. Fire crews from Lancaster County also responded.

Caldwell told media at the scene that the explosion wasn't suspicious, but its cause wasn't known. One firefighter was treated for heat exhaustion, he said.

A Lancaster County man who lives on River Road across the Susquehanna River said the sound woke him and his neighbor. They live about two miles away.

Dan Nephin is a Lancaster Newspapers staff writer. He can be reached or (717) 481-6150. You can also follow @DanNephin on Twitter.