QUEENS, N.Y. (PIX11) — Two workers died in a construction accident at John F. Kennedy International Airport Monday, authorities said.

The workers were trapped under a pile of rubble at the construction site at around 11:10 a.m., according to the Port Authority of New York and New Jersey. A concrete slab fell on the workers while they were down in a 30-foot trench, sources told PIX11 News. Both workers were pronounced dead at the scene.

At the time of the accident, workers were relocating utility lines near a cogeneration plant to support the energy needs of the JFK redevelopment project, according to the Port Authority.

The workers killed were part of Laborers Local 731, sources told PIX11 News. Several union members told PIX11 that the victims worked for Triumph Construction, whose flag is flying over the construction site where the accident happened. PIX11 News reached out to Triumph Construction but hasn’t received a response.

All construction at the airport has been shut down, officials said. It will remain temporarily halted until safety reviews have been conducted.

Gov. Kathy Hochul expressed sympathy on social media after the accident.

“My thoughts are with the loved ones of two people tragically killed while working on a construction site at [JFK Airport] earlier today. [The Port Authority] is conducting a thorough investigation of the incident,” the governor said.

The construction accident did not impact flight operations at JFK Airport.