The labourers were trapped in the rubble when a mound of mud caved in a 20-feet-deep pit around 9 am. The five — Jitendra, Pushpendra, Pran Singh, Ravindra Singh and Umesh — were inside the pit created as a depression amid a wall of mud and gravel. This wall collapsed on the workers, airport sources said.

The Delhi International Airport Limited (DIAL) — responsible for the airport’s renovation — has hired engineering firm Larsen and Toubro (L&T) as procurement and construction contractors for this terminal.

A DIAL officer said: “The men were taken out by a team from L&T and rushed to the hospital. Teams from the Central Industrial Security Force and the Delhi Police also assisted in the rescue.” An airport source said four could be taken out almost immediately, but the fifth man was trapped inside for long.

Following the accident, thousands working at the site went on a rampage and smashed cars parked nearby. They did not spare the ambulance either, CISF men said.

The offices of DIAL and L&T were also ransacked. At least 15,000 men at the site have refused to continue work though L&T officers were in talks with the families of victims. Officers also said the site has been shut for the moment.

A senior CISF officer said: “Two of the rescued workers were declared dead on arrival at the hospital. The third succumbed to injuries later in the evening.” They were Jitendra, Pushpendra and Ravindra Singh. Pran Singh and Umesh are still admitted in this private hospital. All came from Katni in Madhya Pradesh.