New York City is full of peculiar phenomena—rickety fire escapes; 100-year-old subway tunnels; air conditioners propped perilously into window frames—that can strike fear into the heart of even the toughest city denizen. But should they? Every month, writer Ashley Fetters will be exploring—and debunking—these New York-specific fears, letting you know what you should actually worry about, and what anxieties you can simply let slip away.

When J.R.R. Tolkien considered the phrase “cellar door,” so the legend goes, he was overcome with wonder at how elegant and pleasing the English language could sound if the right combination of words were strung together.

When I, however, a frequent foot-traveler of New York City’s sidewalks, hear the words “cellar door,” something else happens: My blood pressure ticks up immediately as I picture walking across two rusty metal sheet doors covering a deep hole in the sidewalk; the doors suddenly giving way beneath me; and me learning what it’s really like to fall down a flight of stairs in the dark and break both hips at the same time.

If you’ve ever wondered whether you could die falling through a set of metal sidewalk cellar doors, the short answer is, you probably won’t, but … you could.

Google “sidewalk cellar door injuries” and your search results will mostly fall into two categories: worst-case-scenario, cautionary-tale news reports (“Texting lady tumbles through open sidewalk doors,” “Man dies falling through cellar doors in Brooklyn”) and New York City law firms eager to explain to you what your rights are if you get injured in a cellar-door accident.

One of those is Pospis Law, PLLC, and firm owner Michael Pospis, who practices personal injury law, reassured me that injuries from cellar doors don’t happen nearly as often as other slip-and-fall injuries (like those that result from tripping on uneven stairs, cracks in the sidewalk, and “things left on sidewalks that shouldn’t be there”).

One reason cellar doors—holdovers from the 19th century, before the city’s sidewalks came under more strict regulation as public spaces—tend to cause relatively few incidents might be that they present a visible hazard to pedestrians, especially when open.

“Walking on sidewalks as pedestrians, we self-organize,” says Renia Ehrenfeucht, co-author of the book Sidewalks: Conflict and Negotiation Over Public Space and chair of the Community and Regional Planning department at the University of New Mexico. “If there actually ends up being an obstacle, the people ahead of you will start veering and you’ll start doing that as well.”

Additionally, Ehrenfeucht says, New Yorkers are among the nation’s savviest and fastest-reacting pedestrians—especially compared to pedestrians in smaller cities and cities in the South and the West, where sidewalks are less crowded. “Think about the complexity of maneuvering a New York City sidewalk,” she explains. “Hundreds of people, in and out of doors, in and out of the subway, entering flows of traffic, going different directions at intersections.” New Yorkers tend to become “very skilled at making their way on the streets.”

And when Ehrenfeucht studied the sidewalk navigation habits of people standing in line at food trucks, she noticed something else: “It was remarkable how good people had become at walking while looking at their phones.”

Still, questions that come up in a cellar-door personal injury case, Pospis says, could feasibly include, Was the injured person texting? Were they on the phone? and Were they distracted and not looking where they were going? So while you should take comfort in knowing your hard-won, hypervigilant New York pedestrian instincts probably won’t let you fall into an open cellar door, it’s important to be actively alert.

Closed cellar doors, meanwhile, present something of a different, and equally harrowing, potential ordeal.

The New York City administrative code states that closed cellar doors that deflect, or bend, more than one inch when walked on are a “substantial defect” and “a hazard,” and that it’s the abutting building owner’s responsibility to replace or repair cellar doors if they do. Of course, metal cellar doors get old and corroded eventually, and realistically speaking, since it’s something of an honor system, sometimes they aren’t replaced until there’s a complaint.

So you should be able to walk right on top of a closed cellar door, in theory. But in practice? “I think people assume that because the doors are closed, they are necessarily locked, securely, so that if you walk over them they won’t give way,” Pospis says. “But I think it’s probably a good idea to assume that the doors are not going to support your weight through the life of them.”

Pospis also managed to introduce me to a whole new variety of cellar-door heebie-jeebies I’d never even considered: The only calls he’s gotten in the last few months related to cellar doors, he says, are about injuries sustained when cellar doors opened while someone was about to walk over.

“The moment they were passing it, a worker from the business was coming up from underneath, and they opened up the door,” he explains. “And of course, [the pedestrian] has to maneuver around the sudden cellar door [opening]. They lose their footing.” That can lead to injuries like bruised knees or ankles, bent or fractured wrists from breaking falls, and even head injuries from falling on the sidewalk.

If there’s a right way to reduce your sidewalk cellar door anxiety, it’s probably the obvious one. “If you have a choice of places to walk, and one of those choices is directly on top of a cellar door and the other is on the sidewalk proper,” Pospis says, “you should definitely choose the sidewalk.”

Got a weird New York anxiety that you want explored? E-mail tips@curbed.com, and we may include it in a future column.