A Navy SEAL candidate died, whereas, another was hospitalized immediately after completing the grueling “hell week”.

Hell Week is one of the earliest gruesome tests in the training program of the forces.

According to the reports, 24-year-old Kyle Mullen, who belongs to Manalapan, New Jersey was shifted to Sharp Coronado hospital in Coronado California where he was pronounced dead.

According to the officials, an investigation is underway to determine the cause of death of the Navy SEAL candidate.

Another Navy SEAL candidate, whose identity was not made public, was also shifted to the Naval Medical Center in San Diego on Saturday after the completion of hell week. The second candidate is said to be in stable condition now.

According to the Navy, both the Navy SEAL candidates had successfully completed hell week – which is a supposedly necessary assessment for the first phase of “basic underwater demolition SEAL (BUD/S) training.” Hours after completing the course, both candidates reported extensive symptoms and were taken to the emergency unit immediately.

The official statement from the navy did not reveal what were the symptoms.

“We extend our deepest sympathies to Seaman Mullen’s family for their loss,” Rear Adm. H.W. Howard III said in one of the statements. “We are extending every form of support we can to the Mullen family and Kyle’s BUD/S classmates.”

The BUD/S is a training which is commonly known as Hell week because of its excruciating intensity. It lasts for about a week where the navy seal candidates are required to survive with not more than four hours of sleep while performing a series of physical activities such as swimming, running, and many others to check their mental toughness and physical endurance. It is also notable that only 25% of the Navy Seal candidates make it through to Hell Week and continue further.