On 21 April 2021, Air Chief Marshal Hadi Tjahjanto, Commander of the Indonesian National Armed Forces, reported that Nanggala was believed to have disappeared in waters about 95 km (51 nautical miles) north of Bali.[26][lower-alpha 2] Indonesian Navy spokesperson First Admiral Julius Widjojono [id] stated that Nanggala had been conducting a torpedo drill, but failed to report its results as expected.[27][28] The navy stated that Nanggala had requested permission to dive to fire a SUT torpedo[15] at 03:00 WIB (20:00 UTC, 20 April).[29][30] Around an hour after being given clearance, the boat lost contact with surface personnel.[6][32] According to the navy, at around 04:00 WIB Nanggala should have been flooding its torpedo tubes in preparation for the firing of the torpedo.