An ironworker helping install a green roof on Barclays Center in Brooklyn was killed Feb. 24 when a load of steel joists rolled off a delivery truck and crushed him, says Joe DePlasco, a spokesman for developer Greenland Forest City Partners.

Peter Zepft, 52, was acting as a flagman when a delivery truck driver was unstrapping a load of steel trusses in preparation for a crane pick, officials say.

The load shifted and one or more joists fell off the truck, striking Zepft, who died at the scene.

DePlasco adds that Zepft was an employee of Massachusetts-based James F. Stearns Co., a steel erector company and subcontractor of Bankers Steel, which is working with Hunt Construction, the construction manager for the green roof installation.

The DOB has issued a full stop-work order at the site as well as an environmental control board violation for failure to safeguard a worksite. The Occupational Safety & Health Administration (OSHA) is conducting an investigation. “The only work taking place right now is mandated work related to staging of materials,” DePlasco said Feb. 25.

According to Greenland Forest City Partners, there have been no other fatalities throughout the construction of the arena or Atlantic Yards.

The developer has issued the following statement, “All of us at Greenland Forest City Partners and Barclays Center extend our most heartfelt condolences to the worker’s family and friends. We are currently working with all relevant agencies to determine what caused this terrible tragedy.”