NEW YORK >> Ariadna Phillips was close to panicking. It was nearing midnight in the Bronx, and she was scrambling to find food for an older woman in the neighborhood who was going hungry after deliveries of federal food aid had run out.

For the past few weeks, Phillips, 40, who organizes a mutual aid group in the South Bronx, had been working frantically to gather enough food donations for those left in the lurch after a federal program stopped temporarily at the start of the year, and then again, a few weeks later, when it ran into logistical problems.

A year ago, as the pandemic engulfed New York, mutual aid groups like hers quickly formed as stopgaps meant to help tide people over during the worst of the crisis.

But even as the pandemic begins to subside, the economic and public health damage it has inflicted persists, especially in less well-off corners of New York City that have been particularly hard hit by an outbreak that has disproportionately hurt poor people and communities of color.

Mutual aid groups that were formed largely ad hoc to address temporary needs are now facing challenges they are not well-equipped to take on: recruiting and retaining a sufficient number of volunteers, securing enough donations of money and goods to keep going, and finding space to serve people.

A group that came together in the spring to offer free mental health care to front-line workers is trying to enlist more established community-based groups to bear part of the burden by organizing group therapy sessions and providing them in Spanish and Mandarin.

“There are hurdles that come with reaching out for mental health services that are far beyond just the pandemic,” said Dr. Nicole Andreoli, a psychologist in Manhattan and one of the group’s organizers. “People really were in kind of like a fight-or-flight mode, kind of frozen. When this ends, we’re expecting to see the trauma response increase.”

Phillips is struggling to find donors to fund a consistent supply of food and volunteers to go on late-night food runs to fill community refrigerators and to map distribution routes and manage logistics so food will be fresh when it reaches people.

The group is also trying to develop an app to track all the roughly 100 community refrigerators in the city and notify users when they are filled with food.

“A lot of the time the fridges are empty, and I can’t imagine how that feels for somebody to be trekking God knows how far,” said David Arvelo, a member of South Bronx Mutual Aid who is working on the app. “It’d be a huge boon for people just needing to know when the fridge is filled.”

Mutual aid — a collective, coordinated effort to help those in need — is not new. But the pandemic, the biggest public health disaster in a century, set off a major wave of mutual aid campaigns with at least 100 groups forming across the state, half of them in the city, according to Mutual Aid Hub, which tracks such organizations.

Nationwide, there are over 800 such groups, though the number is likely to be higher given that many are small and informal. The groups are in larger cities, like Miami, Chicago, San Antonio and San Diego, but also in smaller towns like Columbia, South Carolina, and Butte, Montana.

At the beginning of the pandemic, mutual aid groups helped people with basic necessities like food, clothing, even hand sanitizer. But as the crisis drags on, the groups have broadened their mission, providing Wi-Fi routers so students can access school, mental health counseling and even veterinary care to pets belonging to low-income people. Groups have also played a role in various volunteer efforts to help people sign up for COVID-19 vaccines.

“We’re not looking to necessarily put a Band-Aid on these major crises that are in front of us,” said Yves Voltaire, who lives in Harlem and runs a community refrigerator that offers free food and produce in uptown Manhattan. “It’s about building the world we want to see.”

Two stimulus bills passed by Congress have not prevented people from losing their jobs, being unable to buy enough food and lacking access to social support, said Eric Klinenberg, a sociology professor at New York University and the author of a forthcoming book about mutual aid and the pandemic titled “2020: A Social Autopsy.”

The emergency federal aid was not available to immigrants in the country illegally, and the grinding nature of financial challenges has stretched the limits of how far official assistance can go. It is not clear if help for those immigrants will be part of the coronavirus aid package that is now winding its way through the Senate.

“Government aid has reached just a fraction of the people who need it,” Klinenberg said. “Millions of Americans are in dire straits today, and mutual aid networks are delivering the goods.”

The groups have proliferated thanks in part to technology.

Volunteers have organized over WhatsApp and Slack. Apps have connected donors directly to financially strapped artists, laid-off bar workers and other gig employees. Some groups have developed software similar to that used by food delivery companies to make distributions more efficient.

But the work has become more difficult to sustain as the pandemic persists, especially because New York has suffered a heavier financial blow than most other major U.S. cities.

One group, NYC Mesh, has been trying to install rooftop routers in some so-called Wi-Fi deserts in Queens and the Bronx, where children have a hard time accessing remote schooling. It is also trying to bring broadband into buildings and homes, but that requires digging up part of the street to lay cables, “which is an expensive thing to do,” said Brian Hall, a member of the group.

Connecting broadband to a single building can cost $10,000, Hall said, which exceeds the group’s financial resources. Volunteers are doing all they can, he added, “putting antennas on roofs and internal wiring in the buildings.”

At NYC COVID Care Network, Andreoli said that the pandemic had exposed gaps in care, and her group is having to help people, from delivery workers to grocery store employees, find mental health providers who are taking on new patients or identify affordable options or in-network providers.

Because of the scale of the problem, the group is applying to become a nonprofit, which would make it eligible to receive public funds and private grants.

Mental health hotlines created by the city at the start of the pandemic are not really a long-term solution, Andreoli said.

“If you need something more than just this one-time thing, something that’s a little bit more sustainable, there really is nowhere to go,” she said.

In the Bronx, where many essential workers live and where the unemployment rate is the highest in the city, Phillips has been applying the survival skills she learned growing up in the borough to help lead her group.

As a child, Phillips relied on food and clothes given to her family by friends and neighbors after her father died, reinforcing her belief that mutual is what “so many of us Latinas, so many of us women of color, know exists for us to survive.”

She was accepted at Princeton University but couldn’t afford to pay for student dining, so she lived off free food offered by the university’s associations and clubs, she said. She shared the food with two friends who came from similar backgrounds.

“We all took care of each other,” she said. “It was the most foundational form of mutual aid.”

This winter, she put that experience into practice. One night, not long after midnight, Phillips was walking out of a neighborhood grocery store with bags of donations from the owner, who had helped her out of binds in the past.

Phillips phoned Maria Sanchez, the older woman whose refrigerator was nearly bare.

“Maria? We have your groceries,” she said. “See you soon.”