Two construction workers died in an accident at John F. Kennedy International Airport on Monday. Officials said that a concrete slab fell on top of the victims, who were working inside a 30-foot trench, trapping them under the rubble for more than an hour. First responders were eventually able to pull the workers out of the trench, but both were declared dead at the scene. Due to the incident, all construction at JFK has been halted, and the Port Authority will be “conducting a thorough investigation and will be cooperating with all other investigative agencies,” per a press release. The incident happened just after 11 a.m. local time.