Four workers were injured Monday morning when scaffolding collapsed at a Hudson Yards construction site, authorities said.

Three of the individuals suffered minor injuries, while a fourth was being treated for severe but non-life-threatening injuries, according to the FDNY.

The injured workers were taken to NYC Health + Hospitals/Bellevue and St. Luke’s-Roosevelt Hospital Center, authorities said.

It’s not immediately clear what caused the scaffolding to collapse, authorities said.