An investigation is underway after a beam fell on a crane at a construction site in Queens, killing two workers, the NYC Department of Buildings said.

The crane was lifting a 6,500-pound beam when the beam came loose, crushing the operator in the crane cab, DOB officials say. The 47-year-old crane operator, identified by police as George Smith of Brooklyn, and a flag man on the ground, identified as 43-year-old Alessandro Ramos of Jamaica, Queens, were killed.

"This was a tragic accident - two people will not be going home to see their families tonight," NYC Department of Buildings Commissioner Rick Chandler said.

The construction site is in Briarwood near where the Van Wyck Expressway meets the Grand Central and Jackie Robinson parkways.

NYC Community Alliance for Workers Justice crane operators advocate Eddie Jorge said, while he did not know the details of the accident, it was not safe to operate cranes while winds were gusting at more than 40 mph - as they were on Tuesday.

"These workers go into work everyday not knowing of they're going to come back home. That shouldn't be a price that you pay with your life," he said.

Last winter high winds contributed to a deadly crane collapse in Tribeca, prompting the city to enact new regulations for crane operations on windy days.

However, Chandler said it was unlikely wind played a role in Tuesday's incident.

"At this time, it appears that there was likely a rigging failure that resulted in the beam coming loose and falling to the ground.

"However, we have not made any final determinations," he said.

Neither the company the crane operators worked for, CRV Precast Construction, nor the crane supplier, Cranes Express, had any comment on the incident.

The Buildings Department said the work site had no open violations and the crane operator had no discipline history. The crane had passed its annual inspection in June 2016.

The men's remains were trapped for much of the day by tons of steel. The medical examiner arrived late Tuesday afternoon.

Neighbors say the construction is an extension of an apartment complex.