TAMPA, Fla. (WFLA) — Authorities are investigating the deaths of three snorkelers who died in three separate incidents in the Florida Keys over the past week, the Miami Herald reported.

The first incident, which was described as a “fatal boating accident,” occurred Monday in the Lower Keys.

The Florida Fish and Wildlife Commission said one of its officers was in the area and learned a snorkeler had disappeared. The man’s body was found several hours later.

“Preliminary information indicates head trauma from a possible vessel strike,” FWC spokesman Jason Rafter said in a statement.

The agency is looking into whether the accident involved one of its patrol boats, the Herald reported.

“Due to the FWC vessel in proximity at the time and location the accident may have occurred, the FWC has requested that the Florida Department of Law Enforcement conduct an independent investigation of the incident to ensure complete transparency,” said Rob Klepper, a spokesman for the FWC Division of Law Enforcement said in an email to the newspaper.

“This is an active and ongoing boating accident investigation,” Klepper added.

The man’s name was not released.

The next morning, an Englewood man died while snorkeling in Sawyer Channel, which is also in the Lower Keys, the report said.

According to the Monroe County Sheriff’s Office, the man, Kale Dailey, 53, stated he was feeling ill, and asked to return to a private boat. When his condition worsened, he was helped onto the boat and someone called 911. FWC officers responded and brought him to shore on Cudjoe Key, where he died, the sheriff’s office said.

On Wednesday, a Tampa man was snorkeling near Bluefish Channel when he started to lose consciousness. The 51-year-old was taken to Lower Keys Medical Center on Stock Island and pronounced deceased.

He was not identified.

Each year, snorkelers flock to the Keys to participate in Florida’s two-day mini-season for spiny lobster. The event began Wednesday and ended Thursday.