OCEANA COUNTY, MI - A man who died at the conclusion of the five-day Electric Forest festival had taken a fatal drug cocktail that, like the one that contributed to the death of another festival-goer a week earlier, included the horse tranquilizer ketamine.

Michael John Stephenson, 22, of Lansing was found in medical crisis as festival-goers were packing up to leave the morning of June 27, police reported earlier. He later died, and an autopsy found the death was due to a drug overdose, said Sgt. Scott Rios of the Hart Post of the Michigan State Police.

Stephenson died of "acute cocaine, methamphetamine and ketamine toxicity," Rios said.

Just a week earlier, Matthew Vo, 29, of Southfield was found dead in Lucky Lake during the four-day Lakes of Fire festival. The two festivals -- Electric Forest and Lakes of Fire -- are held in very close proximity near the tiny village of Rothbury in Oceana County.

Vo had drowned June 20 in the lake, and Oceana County Sheriff Lt. Craig Mast said a drug cocktail had contributed to his death. Vo had taken cocaine, alcohol, marijuana and ketamine which likely rendered him unable to swim, Mast said. It's believed the ketamine had raised Vo's body temperature so high he was trying to cool off in the lake, he said.

Electric Forest draws tens of thousands who camp and listen to music performed on multiple stages at all hours of the day and night. The Lakes of Fire Festival at Lucky Lake Campground is described as a collaborative celebration of art, fire, music and friendship, and is a branch of the Burning Man Festival in Nevada.