A missing Indonesian submarine was found in the Bali Sea, split into three pieces on the seafloor. The crew of 53 are confirmed dead and their families, along with the Indonesian people mourn the huge loss.

The vessel lost contact with the Indonesian navy during a military test Wednesday when it was preparing to conduct a torpedo drill. Though the search for the vessel remained optimistic, on Saturday, the search party “moved from the ‘sub miss’ phase to the ‘sub sunk.’”

Indonesian Navy Chief of Staff Adm. Yudo Margona held a news conference, where he explained the search process and showed debris from the missing submarine. A torpedo straightener and Islamic prayer rugs from the submarine had been found, but the missing vessel had not yet been located.

The search was carried out in an area of the Bali Sea that is 850 meters (2,790 feet), which Margona admitted “presents many difficulties.” The navy originally suspected the submarine had sunk beyond its collapse depth of 200 meters (655 feet), to a depth of 600-700 meters 2,000-2,300 feet). The ship was eventually found and the crew of 53 confirmed dead.

The area in the Bali Sea where the submarine lost contact was scanned by Indonesia’s Rigel warship. The warship used sonar and a magnetometer, according to Indonesia military commander Air Chief Marshal Hadi Tjahjanto, and a submarine-sized ship was found. The warship then launched a remote-operated vehicle to get a clearer image of the area, and the missing submarine was identified.

“We found and confirmed an image of Nanggala submarine parts, like horizontal steering, anchor, exterior body, vertical steering, and other submarine parts like safety suits for crew,” Tjahjanto said. “Based on that authentic proof I declare here that the Nanggala submarine sank and all of the crew died.”

Margona said that the sunken submarine was broken into three parts, and among the objects found at the site was a submarine escape immersion suit. It is assumed that the crew attempted to escape the vessel before its imminent demise using the immersion suits, but were too late.

“This suit is only used to escape in emergency situations. Normally it is stored inside the box, but since we found it outside we believe that the crew were going to wear it but they had no chance,” Margona explained.

The cause of the Nanggala submarine’s demise has not been revealed but Margona confirmed that it was “not a human error, but a natural/environment factor.” It was likely cracked due to heavy pressure on the vessel.

The crew, known as the Golden Shark unit, were all given honors and an increase in rank, according to Tjahjanto, and the Air Chief Marshal extended his condolences to their families. Indonesian President Joko Widodo also offered his condolences to the families of the crew, expressing that “This tragedy shocked all of us. Not only the families of the 53 crew members… but also the entire Indonesian people.”

The Nanngala was a German-built Type 209, a 44-year old submarine. It was one of five submarines Indonesia had, including one other German-built Type 209, and three newer South Korean vessels. Residents of the East Java town of Banyuwangi, the location of the naval base conducting search and rescue operations, joined nationwide calls for the modernization of Indonesia’s defense forces.

“This can be a learning point for the government to advance its military technology and be careful in how it uses its (existing) technology because its people’s lives are at stake,” 29-year old resident Hein Ferdy Sentoso, said. Indonesia has been attempting to revamp its military capabilities, but as of now, it still uses old equipment. The consequences have been deadly in recent years, including the latest tragedy aboard the Nanngala.