A Step to Lose Face Over Artists have done it. Athletes have done it. A father has done it with a boy in his arms, fumbling the child briefly before corralling him just in time. Criminals have done it, and police officers, too, though never in succession, in the heat of a chase, to anyone's knowledge. And if you have ever passed through the 36th Street subway station in Sunset Park, Brooklyn, leaving through the exit beside a small cemetery plot on 36th Street and Fourth Avenue, residents say that you have most likely participated in the same ritual: stumbling over the one step, sixth from the top, that stands taller than the rest. On Wednesday, a filmmaker from the neighborhood, Dean Peterson, posted an 87-second video montage online showing travelers tripping on the stairs. By day's end, it had reached an audience of more than 300,000, including at least a few officials at the Metropolitan Transportation Authority. Hours after the video was posted, in what maintenance workers classified as perhaps the fastest response to a customer complaint in agency history, a crew was dispatched to inspect the step. "I think everybody is sort of shocked," Mr. Peterson, 26, said. I almost wish I made a video about something bigger. But on Thursday, with the stairway blocked off, workers struggled to hone in on the problem. Robert Miller, a system safety specialist for the agency, said the culprit appeared to be an excess of adhesive cement buildup beneath the panels that are placed atop the steps. This caused the nosing to be pitched, he said. No, a worker countered, the problem was uniformity. All the steps needed to be the same height and, as even a glance could prove, this was not the case. But the thought was quickly dismissed. Any staircase in the city might have adjacent steps that vary by a quarter of an inch. A tape-measure exercise at the subway exit across the street confirmed this. Kevin Ortiz, a spokesman for the transportation authority, said stairway design guidelines mandated that risers be a minimum of six inches and a maximum of seven, with an allowable variance of three-eighths of an inch. The issue, then, appeared to be the steepness of the ascent. The steps preceding the perilous one were roughly seven or seven and a quarter inches, said one mason, putting away his tape measure on Thursday morning. The rebellious step was eight inches. By 11 a.m., a plan called for only the platform preceding the eight-inch step to be raised, easing the incline. Moments later, another worker suggested a different tack: shave a piece off the top of the tallest step. Heads nodded. The man retrieved his hammer drill. A colleague fetched a broom and a white sack. And as morning turned to afternoon, the crew seemed to have nearly completed its work. "Take off half an inch," one worker said, squinting. Now you're in the ballpark. Later in the day, though, Mr. Ortiz, the agency spokesman, said alterations to a single riser would not suffice. The entire stairway would need to be refurbished - though he did acknowledge that one step's excessive height was "consistent with the evidence provided in the video clip." He said the staircase would be reopened on Saturday. Among residents, many of whom had seen the video before happening upon the construction site on Thursday morning, the repairs came as a relief. Abel Chino, 42, who sells ice cream and tamales from a pushcart at the top of the stairs, said in Spanish that "almost 70 to 80 percent" of travelers had starred in some version of the typical routine: a stumble; a brief scan of the area, perhaps, to ensure that no one saw; and then a sprightly finish, once balance was restored, to make up for lost time. Recently, Mr. Chino said, one woman was not so lucky. "She tripped and fell all the way down to the bottom," Mr. Chino recalled. He allowed himself a brief smile. "She was O.K.," he said. She kept walking. Meejin Richart, 25, who has lived in Sunset Park since last year, said a camaraderie had developed among stumblers. "It's embarrassing, but here everyone knows, so it's a little less embarrassing," she said. You just give a knowing look. Ben Dzamba, 30, a Web developer who has lived in the neighborhood for two years, said he had an epiphany after watching Mr. Peterson's video. "Now that I think about it, I have tripped," he said. I never put two and two together. At least one passer-by wondered what the fuss was about. She has lived in Sunset Park all her life, she said, and did not think the stairway dust-up rose to the level of community scourge. She would not offer a name, she said, but proudly provided her age, 77, and a small piece of advice. "You see a platform," she said, raising both arms for the big reveal. You step.