A crew member working on the set of the upcoming action Western film “Lone Ranger,” starring Johnny Depp, has died this morning after drowning on the set

Reports coming out of the Los Angeles movie set indicate that the man was a diver who was working under water in a tank before “something went wrong” and he went into cardiac arrest.

According to TMZ, 911 responded to a call made by someone on the crew who reported a medical emergency. When responders arrived to the, scene the man was in full cardiac arrest.

Cardiac arrest, a variation of a heart attack, is the cessation of the pumping function of the heart. Simply put, arrested blood circulation prevents delivery of oxygen to the body.

TMZ reports that the unidentified crew member was helicoptered to a nearby hospital, but EMTs were unable to restart his heart on the flight. Law enforcement sources told Thirty Mile Zone he was pronounced dead at the hospital.

Filming for the “Lone Ranger” commenced the first week of March. The studio film, which boasts a $215 million budget, stars Armie Hammer in the lead role and Johnny Depp as Tonto.

It’s due to hit theatres in July 2013