NEW YORK (AP) — A fire and explosion at a shipyard on New York City's Staten Island has injured at least 16 people, including three with serious injuries, the New York Fire Department said.

Someone reported two workers trapped in a confined space at the dock at about 3:30 p.m. Friday, and responding firefighters found a fire burning in the basement of a large metal structure at the dock, said Joanne Mariano with the fire department's press office.

Crews were still fighting the fire when a major explosion occurred at the site roughly 50 minutes later, she said.

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Emergency workers had counted 16 people on site with injuries by 5 p.m., Mariano said, including two firefighters and one civilian with serious injuries. Two additional firefighters had moderate injuries, and the rest had minor injuries. Crews were still working on finalizing the patient count, she said.

There were more than 200 firefighters and emergency medical personnel from 68 units at the site Friday evening, Mariano said. The cause of the fire and explosion is still under investigation.

The dock is home to several businesses, including a coffee roasting company and a self-storage facility. The shipyard used to be owned by the Bethlehem Steel Company, which built ships for the U.S. Navy during World War II.