LEXINGTON, Ky. (AP) _ Heavy smoke and fire engulfed the Islamic Society of Central Kentucky, but the cause wasn't immediately known, officials said.

Investigators were on the scene and were expected to work through the night, Battalion Chief Randy Gilliam said early Thursday.

One firefighter was hit by debris inside the building and hospitalized as a precautionary measure, Gilliam said.

No one was in the building during the fire, said Imam Mahmoud Shalash, spiritual leader of the Islamic Center of Lexington.

``Everybody is sad, but we are glad no life was lost,'' Shalash told the Lexington Herald-Leader.

The center was being renovated into a Muslim elementary school.

Gilliam said it was too early to speculate on the cause of the fire. Storms carrying lightning struck the region late Wednesday.