CORONADO, Calif. — Just hours after finishing a grueling training, two Navy SEAL candidates were rushed to the hospital, one of them died at Sharp Coronado Friday afternoon.

Their Basic Underwater Demolition Seal Training (BUD/S) class had just completed what’s known as “Hell Week”.

““It is a miserable time, it is well-named,” said Paul Anderson, a retired Navy Seal Chief. “It’s a gut check. You get approximately four hours of sleep the whole week. You are constantly doing physical evolutions whether it’s physical obstacles, going in and out of the surf zone with your boats, running, you are constantly wet and you are always sandy.”

Veteran Paul Anderson said it’s hard to know what caused the undisclosed sickness the two sailors suffered.

Navy officials said the sailors reported symptoms after training.

“They may have had pneumonia and went home to try and cover it up because if you are sick or injured you can be held back from your class,” Anderson said. “I think they didn’t want to lose their place and have to go through all this again so they may have tried to hide their symptoms, though again I don’t know.”

It’s not clear what these SEAL students went through during this first phase of training, but Anderson shared what could have happened.

“You know that is kind of a common thing, aspirating some water in the pool or in the ocean is very easy to do,” Anderson said. “I hate to speculate what happened, but I don’t think it was from the lack of attention from the instructors or the medical staffing.”

In a statement regarding the death, 52nd District Congressman Scott Peters said, “My prayers are with the family and loved ones of the deceased during this very difficult time, and I wish for a full recovery of the other candidate reported injured yesterday. These courageous, talented sailors were on their way to becoming some of our country’s most elite military personnel. We must find out what transpired so we can do whatever we can to keep others safe.”

The last death reported was May of 2016 when 21-year-old Seaman James Derek Lovelace died while undergoing a BUD/S pool exercise at Naval Amphibious Base Coronado.

The medical examiner ruled his death a homicide by drowning, but no criminal charges were filed.

Navy officials plan to release the name of the deceased Navy SEAL candidate 24 hours after his family is notified.

In the meantime, they are investigating the cause of his death.

At last check, the other sailor is under close medical watch at the Naval Medical Center San Diego.