A portion of the border wall of a residential society in Noida collapsed this morning, crushing four construction workers. At Jal Vayu Vihar, a sizable housing development in Noida's Sector 21, bulldozers were brought into action to free 12 workmen who were submerged beneath the debris.

"Rescue and relief measures have been launched. Fire department personnel and police, including senior officers, are at the spot," news agency PTI quoted a police officer as saying soon after the incident.

Yogi Adityanath, the chief minister, has sent his sympathies. According to a tweet from his office, he ordered senior officials to head straight to the scene of the wall fall and begin relief efforts on a war footing. The Chief Minister has also given instructions to staff to see to it that those hurt in the incident are treated properly.

District magistrate Suhas LY rushed to the spot after the incident. "Rescue operation is underway. Details of the injured people are being ascertained. The area is being searched as a precautionary measure. All teams are present here," he told the media.

The district magistrate said that the Noida development authority had given a contract to repair the drainage system near the apartment complex. "We have been told that when labourers were pulling out bricks, the wall collapsed. It will be investigated," he said.