In a joint operation, an Indian Air Force Advanced Light Helicopter (ALH) winched Navy's divers to measure the depth of a glacial lake formed upstream of Tapovan in Uttarakhand following the devastating flash flood, the Navy said on Sunday. At least 65 people were killed and 139 are missing after a glacial disaster in the state's Chamoli district on February 7. The artificial lake was formed over Rishiganga after the calamity. The operation by the naval divers took place at a height of 14,000 feet above the mean sea level on Saturday. Watch the full video for more details.