A Texas man died while diving off of Key Largo in Florida.

Monroe County Sheriff's Office on Thursday said that 57-year-old Thomas Pickett of Rockwall, Texas, was diving at in water about 20 feet deep at Elbow Reef on Wednesday.

His dive partner says he did not appear to have trouble during the dive, but other witnesses say Pickett surfaced and began to have trouble.

Authorities say he was pulled into the boat and was unconscious. He stopped breathing and crew on board the boat began to perform CPR. Paramedics met the boat at shore and transported Pickett to a hospital where he was pronounced dead.

An autopsy will be done to determine the cause of his death.