Washington state fire authorities are investigating the cause of a barn blaze that claimed two horses’ lives.

Duvall, Washington, Fire Chief David Burke said firefighters responded to a report of a fire in a barn in Duvall early on April 13. One Miniature Horse died in the blaze, Burke said, while five other horses were rescued.

“But one was euthanized the following day due to its burns,” Burke said.

While the fire’s cause remains under investigation, Burke said the site of the blaze was an outbuilding that contained appropriate wiring and electrical outlets; “That kind of wiring is not something we see often,” he added