OCALA, FL—FEBRUARY 18, 2012—The February 10 explosion of a hyperbaric oxygen chamber at a Florida equine facility killing one woman and a horse was caused by contact from the horse’s steel shoe with the chamber according to report by the Marion County Sheriff's Office.

The Sheriff’s Office concluded that the explosion, at the Kentucky Equine Sports Medicine and Rehabilitation Center in Ocala, Florida was an accident. The blast also injured a second woman.

Erica Marshall, a 28-year-old employee of KESMARC, was killed in the explosion. Sorcha Moneley, 33, of London, England, who was at the facility to look at the oxygen chamber for possible use in Europe, was also injured in the accident.

According to the report, Moneley said the horse in the chamber, who had steel shoes on his hooves, began kicking and knocked off a part of the chamber's protective padding, revealing a metal surface. When he kicked again, a spark was created when one of the shoes connected with the metal surface.

As Marshall attempted to return the chamber to normal pressure, Moneley left to call emergency personnel, the report said. As Moneley departed to call 911, according to the report, “she looked back and saw Erica staring at the monitor and crying.”

Moneley told the investigators she then heard two explosions in rapid succession. Moneley said the second explosion was much larger than the first. Moneley said she was about 20 feet away from the chamber when the explosion occurred and that the second one “knocked her down and took her breath away,” according to the report.

Moneley said she "was aware that there were some problems with the valves on the chamber leaking” and that the facility manager was attempting to have the problem reviewed by an engineer. According to the report, KESMARC manager Leonora Byrne said that Marshall had operated the chamber for two years.