The natural disaster that struck Uttarakhand's Chamoli district has so far claimed as many as 30 lives, while more than 150 people are still missing.
One Rajesh Kumar was rescued to tell the harrowing tale of survival.
Thirty-one people were confirmed dead but at least 170 others remained missing after the glacier broke off a mountainside, triggering a flash flood through a valley in Uttarakhand.
On Sunday, floodwaters swamped a nearby hydroelectric power complex where Kumar and his colleagues were working 300 metres (nearly 1,000 feet) inside a tunnel.
"We didn't think we were going to make it," the 28-year-old told AFP from his hospital bed.??
"Suddenly there was a sound of whistling... there was shouting, people were telling us to come out. We thought it was a fire. We started running but the water gushed in. It was like a Hollywood movie."
The men clung to scaffolding rods in the tunnel for four hours, keeping their heads above water and debris, trying to reassure each other.
"We just kept telling each other -- come what may, we must not let go of the rods. Thank god our hands did not lose their grip," said Kumar.
As the flood coursed down the valley, the water started to recede in the tunnel, leaving it filled with more than 1.5 metres of debris and mud.
"We climbed across the rock debris and forced our way to the mouth of the tunnel," said Kumar.
There they found a small opening but they were not sure where it led.?
"All we knew was that we could feel some air."
Eventually, they saw some light coming through and one of the men got a phone signal and called for help.
There were emotional scenes as Kumar and his colleagues were pulled out of a tiny hole at the surface.?
Some punched the air in joy as they saw daylight, some were put straight onto stretchers and carried away. One man put his arms in the air and then fell face-first into the mud.
Despite their hours-long ordeal, they miraculously managed to escape with just minor injuries.