A portion of the Nanda Devi glacier broke off in northern India Sunday, destroying two dams, which caused a huge wall of water to roar downstream. The massive flood of water destroyed several homes and caught residents off guard.

Indian authorities said that at least nine people have been confirmed to have been killed and 140 people are unaccounted for. Rescue operations are still ongoing in the northern state of Uttarakhand.

A video of the portion of the glacier breaking one of the dams with little resistance was posted online by Indian officials. After the dam was destroyed, a wall of water made its way down the side of a steep hillside.

The Indo Tibetan Border Police said that the Rishiganga hydropower plant was completely destroyed, while the Dhauliganga hydropower plant was badly damaged. Both dams are located along the Alaknanda River, which brings water from the Himalayan Mountains into the Ganges.

Authorities said that at least 16 workers are trapped inside a tunnel in the Dhauliganga hydropower plant. Rescue workers have so far recovered nine dead bodies. Operators of the two dams said that 140 of their workers are still missing.

Following the incident, officials immediately issued a warning to all people living near the banks of the Alaknanda River, telling them to move to higher ground.

In an attempt to mitigate the damage, authorities emptied two dams further down the river. Officials also ordered all boating and tourist activities in the Ganges River to shut down.

Prime Minister Narendra Modi said on social media that authorities are closely monitoring the “unfortunate situation” and the country is praying for everyone’s safety.