Investigators were combing through a New York City shipyard on Saturday trying to find the cause of a fire and an explosion that killed one person and injured more than 30 firefighters and other first responders.

Authorities provided no major updates to the incidents that occurred Friday afternoon in the Mariners Harbor neighborhood on the north shore of Staten Island. Besides investigators, some firefighters were at the site as a precaution Saturday, officials said.

Firefighters were called to the shipyard about 3:30 p.m. Friday on reports that there was a fire, heavy smoke and two workers trapped in a basement area, city Fire Commissioner Lillian Bonsignore said. Less than an hour later, as firefighters and emergency medical personnel were working the scene, an explosion rocked the site, officials said.

A civilian died, and another was wounded. Authorities said a fire marshal and a firefighter were seriously injured, while 29 firefighters had minor to moderate injuries and four emergency medical personnel had minor injuries. All were taken to area hospitals.

“We got very lucky this day,” Bonsignore said at a Friday evening news conference. “We got lucky in the sense that none of our people were killed. It’s unfortunate we had one fatality, and they did everything they could to get to that person.”

The name of the person who died had not been released as of Saturday.

The fire marshal who was injured, Christopher Cuccaro, suffered a fractured skull and brain bleed, said the fire department’s chief medical officer Dr. David Prezant. He was in critical but stable condition.

“We will be watching him very carefully over the next 24 hours to make certain there is not subsequent brain swelling. As long as there is not, he should do well,” Prezant said at Friday’s news conference.

Cuccaro and the other firefighter with serious injuries were wounded by the shock wave from the blast, Prezant said. The firefighter was doing “very well,” he said.

“Thankfully both of these firefighters do not have penetrating injuries and do not have blast injury damage to their organs, to their heart, lungs or abdomen,” Prezant said.

The fire and explosion happened in a 150-foot-by-150-foot (46 meters by 46 meters) metal structure at the back of the shipyard, Bonsignore said. Around 200 firefighters and emergency medical personnel responded.

Richard Oviogor, who was in the area, told WABC-TV that he heard two explosions and what seemed like a “big shock wave.”

The area 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.