The King County Medical Examiner's Office says Olympic equestrian Amy Tryon died of an accidental overdose.
Tryon, who worked as a firefighter for Eastside Fire and Rescue, died on April 12.
The Medical Examiner said Tuesday that toxicology reports show Tryon died of an "acute combined opiate" overdose. The office said toxicology tests showed that present in Tryon's system at the time of her death were Oxycodone, diphenhydramine - an ingredient in over-the-counter cold and allergy medications - and several benzodiazepines: Alprazolam, Diazepam, Lorazepam and Temazepam.
Tryon rode for the U.S. Equestrian Team at the Athens and Beijing Olympics in 2004 and 2008, respectively. She helped the U.S. to a team bronze medal at the 2004 Games.
Tryon competed at the international level for years, winning a gold medal at 2002 World Equestrian Games in Jerez, Spain, as well as being named Chronicle's Eventing Horseman of the Year in 2006.