The 100 block of K Street NE is a dank and gloomy underpass connecting rapidly growing neighborhoods of high-end condos, gleaming office buildings and trendy restaurants. The rumble of trains pulling in and out of Union Station on the tracks above creates a steady din, and the blare of horns and sirens pierces all hours of the day. It often smells.

The underpass is no place to call home, but home is what it’s called by the several dozen men and women whose tents, blankets and belongings cover the sidewalk on both sides of the street. They’ve ended up here from nearby and far away. From Arlington and Adams Morgan, but also Phoenix, the Jersey Shore and Chattanooga, Tenn.

Their numbers have grown over the past year, from a few tents last spring to 30 or 40, depending on the day. The city says that there’s not enough space for pedestrians to pass safely and that the tents present a dangerous obstacle. Health officials posted signs in the tunnel ordering everyone there to move by Thursday.

“Tents and living in tents is not permitted in the District of Columbia, and it’s not safe for the inhabitant. It’s also not safe for the surrounding community,” D.C. Mayor Muriel E. Bowser (D) told reporters at a Wednesday news conference when asked about the K Street encampment. “We also, it should be clear, make our abundant homeless services available to anybody who is living in a tent, and we will continue that very robust outreach to make sure people know what services are available for them.”

The K Street clear-out is the latest move by the District to respond to an increasingly visible homeless population and comes as affordable housing is at a premium. Many of the homeless and their advocates dispute that the city provides adequate drug rehabilitation and mental health treatment.

“We’re horrified at the timing,” said Ann Marie Staudenmaier, staff attorney at the Washington Legal Clinic for the Homeless. “The city picked the snowiest and coldest time of the year to kick 40 people out of their homes.”

Staudenmaier said her organization is exploring a potential challenge to a permanent ban on people staying in that underpass. And she pointedly criticized Bowser for issuing an order that removed homeless from the relative safety and shelter of the underpass.

“I don’t think Mayor Bowser has a lot in common with President Trump, but she is using the same language he does to demonize and criticize people whose only crime is that they’re homeless,” Staudenmaier said.

The men and women living in the underpass say the city’s order means that yet another place they’ve found to reside is being yanked from under them.

“I’m observing the nation, and it’s a crisis,” said Michael Harris, 58, sitting in a wheelchair next to his tent. “With the gentrification situation, I’m sorry, but it’s completely unfair. People are being priced out of the rental market and the purchasing market.”

Wearing a Washington Nationals baseball cap and a jacket with “Lil Mike” inscribed on the breast, Harris is the closest thing the underpass has to a mayor. He has been here seven months trying to keep order, quashing disagreements and encouraging his tent neighbors to keep the block tidy. His tent is filled with clean shirts that are folded, socks and toiletries he provides to anyone who asks. He often wheels his chair along the sidewalk picking up trash and depositing it in a garbage can at the end of the block.

Harris knows that the tents are an eyesore and that the encampment presents problems. He also said he believes the city isn’t coming up with adequate solutions.

“I understand people have a gripe with the homeless in their face, but give us somewhere to move that’s livable and affordable,” Harris said. “I don’t want to be here, but I need to make the best of it.”

There were 6,521 people in the District identified as homeless by the annual Point-in-Time count conducted last January, according to data provided by the Washington Legal Clinic for the Homeless. That included 3,862 adults, 13 unaccompanied minors and 815 families containing 2,646 members. On the night of the count, at least 608 people were living on the street.

The District’s homeless population increased 34 percent between 2009 and 2016, according to a U.S. Conference of Mayors report on hunger and homelessness. It decreased 5.5 percent from 2018 to 2019, according to the Point-in-Time count. That was attributed to a drop in homeless families, even as the number of single adults who were homeless increased.

Many advocates said they believe the Point-in-Time survey severely undercounts the homeless population. The 2020 count is scheduled for later this month.

The city’s decision to evict campers from the underpass is “a brutal reaction to a serious problem,” said Brian Carome, executive director of Street Sense Media, a newspaper and media organization in the District that advocates for the homeless. “People are drawn to these encampments for very logical reasons. They find living in a shelter intolerable and unhealthy.”

Carome disputes the city’s assertions that shelters provide adequate support and health care for the homeless, particularly when it comes to treatment for mental health issues that plague a large percentage of the homeless who live on the street.

Those living in tents on K Street say they’re unsure of their next move. Some will head to nearby underpasses on L and M streets NE. The sidewalks are wider, but there are many others already living there in tents. As those underpasses become more crowded with the new arrivals, the homeless wonder if they’ll soon be removed from L and M streets as well.

Asked at her news conference if K Street was the start of clearing out all homeless encampments, Bowser repeated, “Tents, living in tents, is not permitted in the District of Columbia.”

Residents of adjacent neighborhoods have had mixed reactions, said Drew Courtney, an Advisory Neighborhood Commission member whose district includes the encampments.

“Everyone understands that this is a complicated issue,” Courtney said. “I talk with neighbors and some are really strong advocates for the homeless and others just want them removed, end of story. Most people are somewhere in the middle. People want to do the right thing.”

In August, Robin-Eve Jasper, president of the NoMa Business Improvement District, the influential neighborhood development organization, issued a lengthy public letter calling all of the underpasses “unsafe and unsanitary environments” and urging that “something be done to recognize and protect the right of D.C. residents, workers, and visitors to safely use and pass through public space in NoMa.”

The NoMa Business Improvement District, created by the D.C. Council in 2007, is funded by grants and a tax assessment on properties in a 35-block area roughly west and north of Union Station. Railroad tracks cut through the eastern part of NoMa, creating underpasses in the neighborhood from H Street to Florida Avenue in Northeast Washington.

In her letter, Jasper said NoMa residents had expressed concerns about an increase in panhandling and aggressive behavior and worsening conditions in the underpasses.

“Used and bloody hypodermic needles and other drug paraphernalia, rotting food, trash, broken glass, public nudity, prostitution, sales of illegal drugs, and human urine and feces are encountered by those whose routes take them by the encampments and pervade the space in which encamped individuals are living,” Jasper wrote.

Advocates criticized the letter, saying it was dehumanizing and didn’t offer solutions. A NoMa Business Improvement District representative said Jasper was unavailable for an interview about the city’s order to vacate the K Street underpass.

Aaron Howe, an anthropology PhD candidate at American University who began an ethnography of the NoMa homeless community in 2018 for a dissertation, said the city’s decision to ban tents from the K Street underpass sets a precedent.

Howe said NoMa is an area with ample vacant land that should be made available to the homeless.

“If they want to make a pedestrian safe zone, they can provide a camping safe zone as well,” Howe said.

Wayne Turnage, deputy mayor for D.C. Health and Human Services, said any such camping area is not under consideration by the city. He acknowledged that lack of affordable housing presents a critical hurdle in the quest to provide permanent shelter for the homeless.

“I think the mayor’s position right now is, the best solution to encampments is more affordable housing units,” Turnage said in an interview Tuesday. “In the meantime, we have what we believe is a very effective shelter system that we invest money in each year to ensure that people have somewhere safe and secure to stay, that does not force them to go to the streets and to live unprotected.”

Keesha Rodriguez Davis won’t have to move her tent from the K Street encampment. She doesn’t have one. Davis, 53, has been sleeping on blankets in the middle of the underpass for the past three weeks. She keeps her belongings in a shopping cart.

Davis said her neighbors on the street have been kind. She’s making do. An outreach worker stops by and hands her a wrapped mozzarella-and-tomato sandwich from a local cafe. She’s grateful.

“I wish I could get a tent,” she said, with a smile. “It gets real cold.”

Fenit Nirappil contributed to this report.