Authorities halted construction at JFK International Airport in New York City on April 3 following a trench collapse that killed two construction workers.

The halt order came as the Port Authority of New York and New Jersey teamed with other agencies to launch an investigation into what caused the late morning fatal accident.

A Port Authority police unit received a report at 11:08 a.m. of two workers trapped under construction rubble at a work site at the airport, according to a statement by the agency. 

Both workers were later confirmed dead, officials said in a statement. The workers were identified by the Port Authority as Francisco Reyes, 41, and Fernando Lagunas Pereira, 28. Their employers were not disclosed.

“The Port Authority is conducting a thorough investigation and will be cooperating with all other investigative agencies,” it said in a statement.

Roughly 60 New York firefighters, medics and other personnel descended on the scene and attempted to rescue the two workers.

It is not clear how long they were trapped under debris, with local TV affiliate CBS 2 reporting that it was an hour before first responders managed to pull the pair from the trench.

Rescuers used an excavator, pulleys, ropes and chains to remove rubble to reach the workers. They had been relocating utility lines near a cogeneration power plant at the airport when they fell into a 30-ft trench, CBS 2 reports.

The work was taking place near JFK's Terminal 7, set for demolition to make way as construction moves ahead on a new Terminal 6.

“My thoughts are with the loved ones of two people tragically killed working on a construction site @JFKairport earlier today,” N.Y. Gov. Kathy Hochul tweeted. “@PANYNJ is conducting a thorough investigation of the incident.”

Traffic was temporarily tied up near the rescue scene, although there were no reports of any flight delays caused by the tragedy. The fatal accident comes about five weeks after the failure of an electrical panel sparked a fire that knocked out power at Terminal 1. That outage triggered delays and scrambled flight schedules.