Delaware fire authorities are investigating the cause of a barn blaze that killed a dozen horses.

Delaware State Fire Marshal’s Department Assistant Fire Marshal Michael Chionchio said fire personnel responded to a 911 call reporting a barn fire at Yorklyn Arabians, in Hockessin, on Dec. 21. The barn was visibly involved in flames when fire crews arrived, he said.

Chionchio said 12 horses were killed in the fire and one survived.

The cause of the blaze remains under investigation by the Delaware State Fire Marshal’s Office, Chionchio said