Nearly 300 New York City firefighters were still battling a massive seven-alarm fire in Williamsburg, Brooklyn, nearly 12 hours after the flames were first reported early Saturday. Boats on the East River blasted water on the blazing warehouse as nasty winter winds whipped smoke into Manhattan and ice crept over fire trucks and hoses.

"It's still a very active scene," a spokesman for the Fire Department of New York, or FDNY, confirmed at 5 p.m. EST. No injuries had been reported. Fifty-five engine companies were splitting the work in three-hour shifts due to below-freezing temperatures and 18 mph winds. The fire department said it expects the blaze will take "several days" to fully suppress, the spokesman said. 

The Williamsburg warehouse run by CitiStorage is listed online as a privately run records storage facility that serves the NYC Health and Hospital Corporation, which operates the city's public hospitals and health centers, and other businesses, WNBC, New York, reported. Charred bits of court documents and hospital patient records were seen fluttering around the neighborhood and drifting into the sky.

The HHC said duplicates of vital patient records are kept in electronic form. "We do not anticipate that this will affect our operations," the city hospital agency said in a statement.

Fire officials were initially called to the warehouse around 4:30 a.m. and contained a small fire about 45 minutes later. But at 6:30 a.m., firefighters were called back after a more serious fire broke out, and within hours the fire department had declared it a seven-alarm blaze, indicating the extreme nature of the fire and the level of manpower needed to put it out.

It is not known if the two fires are related, and police officials say they are investigating the causes of both.

Passers-by in the Brooklyn neighborhood wrapped scarves over their mouths to filter out the acrid smoke. “I can’t believe it’s not out by now,” Mark Engel, 41, a lawyer from Long Island, told the New York Times. “It’s like 9/11, you don’t know what you’re breathing, I’m afraid to have my kids here.”