On 10 February 2012, a hyperbaric oxygen chamber exploded at the Kentucky Equine Sports Medicine and Rehabilitation Center (KESMARC) in Ocala, Florida, when a horse inside the chamber started to kick.

Photo: Type of chamber used for HBOT treatment

The horse and a woman were killed in the incident. Another woman sustained injuries, it has been reported.

A local news report indicates that the two women were observing the horse via video feed from a separate room when they saw the horse become agitated and start kicking. They tried to activate an emergency switch to decompress the chamber, but the horse kicked off the protective layer from his steel shoe and made contact with the steel wall of the chamber, igniting a spark that triggered the explosion.

Hyperbaric oxygen therapy (HBOT) involves treating a patient with 100% oxygen under pressure; veterinarians have explained the process increases oxygen levels in blood plasma and promotes higher delivery to all body tissues, including the injured area, to facilitate healing. In horses HBOT is used to treat a range of conditions and acute injuries, including deep wounds, joint injuries, and infections. Horses treated with HBOT are placed in chambers that are approximately 10 to 12 feet in diameter.