Officials at the scene of a building collapse at 42-20 27th St. in Long Island City on June 26, 2017. View Full Caption DNAinfo/Jeanmarie Evelly

LONG ISLAND CITY — The partial collapse of an apartment tower construction site near Queensboro Plaza injured six workers Monday, authorities said.

The workers suffered minor to moderate injuries in the incident, which took place at 42-20 27th St. around 11 a.m. when crews were pouring concrete into a 20-by-20 foot form that collapsed onto the seventh floor below, according to the FDNY and Department of Buildings.

The six hurt workers were taken to local hospitals for ailments that included back, leg and arm injuries, FDNY officials said. All were in stable condition.

The DOB halted all construction and issued a violation for failure to safeguard the site, according to a spokesman.

Ben Foo, who was working at a construction site across the street from where the incident took place, said he heard a loud crash.

"Just one big boom," he said, saying he saw a couple of workers taken away from the scene on stretchers. "A couple of other people were limping."

The Rabsky Group, a Brooklyn-based developer, is building an 18-story apartment tower at the site, according to Department of Buildings records and published reports.

The company did not immediately return a message seeking comment Monday.