A Washington Heights woman was seriously injured Saturday after the sidewalk she was standing on collapsed, plunging her six feet into an abandoned underground vault below.

According to authorities, Mariana Fuentes, 47, was selling flowers on W. 158th Street near Broadway just before 8 a.m. when the sidewalk suddenly crumbled. Several witnesses heard screaming, and neighbors told CBS-2 that it appeared a slab of concrete pinned the woman's leg.

"She was just getting ready, and the floor of the sidewalk that is close to the building, it gave in and ended up collapsing—bring[ing] her down about 8 feet in the basement, and that’s when a piece of concrete landed up on her leg,” neighbor Giovanni Antones told the station.

Firefighters arrived on the scene and raised Fuentes out of the hole on a backboard. She was taken to Harlem Hospital and is in serious but stable condition.

According to neighbors, Fuentes has lived in the area for over two decades, and sells flowers throughout the year to support her two children.

"This is very sad because, a while ago, her husband got run over by a city bus, so they’re now both injured,” an unnamed neighbor told the Daily News. “She’s not going to be able to do any work or do anything anymore.”

The City Department of Buildings issued a partial vacate order for the sidewalk and cellar vault in front of 537 West 158 Street and a neighboring building at 541 West 158th Street, a DOB spokesperson said. Violations were issued to both properties for a failure to maintain the cellars and sidewalks.

"The Department of Buildings has determined that conditions in this premises are imminently perilous to life," a sign near the sidewalk read Saturday. "This premises has been vacated and reentry is prohibited."