An Indonesian navy submarine sank off the coast of Bali on Wednesday, breaking into three pieces, officials said.

The ship’s 53 crew members have been confirmed dead.

Navy officials said they received a signal more than 600 meters (2,600 feet) deep from the submarine’s location early Sunday morning.

An underwater rescue vehicle provided by Singapore was lowered to get visual confirmation of the wreckage.

KRI Nangala went missing after requesting permission to dive during a torpedo drill. The cause of the sinking is not yet clear.

Hadi Tajahanto, the head of the Indonesian army, confirmed that there was no possibility of finding the crew alive.

“I am just sad to say that 53 of the staff on board have died,” he told reporters.

Experts had previously said that the depth of the submarine was well beyond its survival and that it only carried enough oxygen for three days.

 

The Indonesian submarine sank in the Bali, the navy said