Waldon Adams spent nearly every hour of every day helping people who lived as he once had — homeless, addicted to drugs and alcohol, and struggling with mental illness.

He used his personal story to earn the trust of people living on the District’s streets while cajoling those in power to do more, serving on a mayor’s commission that helps set policy and put him in contact with department heads and city leaders.

“He cared passionately about every single person, whether he was talking with someone under a bridge or at the Wilson Building,” where the mayor and city council have offices, said Christy Respress, the executive director of Pathways to Housing D.C., a nonprofit that employed Adams the past five years.

Adams, 60, and his close friend, Rhonda Whitaker, 55, who had also once been homeless and worked as an advocate, were killed Saturday when they were struck by a vehicle while they were taking a stroll at Hains Point at the southern tip of East Potomac Park.

Respress said Miriam’s Kitchen, another advocacy group, plans to honor Whitaker at an upcoming gala. She said Adams “helped more people single-handedly move into housing than any case manager I know.”

News of their deaths spread quickly through the network of advocacy and nonprofit groups that work with the District’s homeless population. Leaders at Miriam’s Kitchen said they were too grief-stricken to talk about Whitaker or Adams, saying in a statement the organization will “honor their memories by continuing to fight for housing justice in D.C.”

The deaths come as the District has seen a rise in traffic fatalities, even with efforts to improve street safety. There were 37 traffic fatalities last year, up from 27 in 2019. As of Tuesday, the city had recorded 15 fatalities in 2021, seven more than the same time last year, police records show.

This month, those killed in crashes include a 4-year-old boy struck by a vehicle in Northwest, a 54 year-old woman hit by a vehicle in Northeast and a bicyclist struck in a chain-reaction crash in Northwest. D.C. Council Member Mary M. Cheh (D-Ward 3) said she was working to bring together a group of local and federal officials to see whether any road or sidewalk safety improvements could be quickly implemented.

U.S. Park Police, the agency investigating the Hains Point incident because the park is federal land, said Whitaker and Adams were struck at roughly 10:30 a.m. and that the driver drove away. Police did not say precisely where Whitaker and Adams were when they were struck or provide other details of the crash.

Sgt. Roselyn Norment, a Park Police spokeswoman, said the driver and vehicle were later found. She said the driver cooperated with authorities.

On Monday, Norment said detectives are working with federal prosecutors “to determine what specific charges will be filed in Saturday’s fatal hit-and-run pending the results of a toxicology report and police investigation.”

D.C. Council member Brianne K. Nadeau (D-Ward 1), who serves on the interagency homeless council, said Adams had sat at tables with department heads and other officials.

She recalled participating on a panel with Adams to discuss homeless issues before residents in Ward 3 and said they faced a feisty crowd. Adams calmed the room when he told them his story.

“He really captivated them and help them understand a different perspective on the homeless and what someone’s experience is when they live on the streets,” Nadeau said.

The lawmaker said there are plans for a city council resolution to honor Adams and Whitaker.

Mayor Muriel E. Bowser (D) said it was tragic that “two people lost their lives in one of the most beautiful places in our city.”

Hains Point is at the tip of East Potomac Park, an island near the Tidal Basin popular with walkers, joggers, bicyclists, and picnickers. The roads, which are shared by motorists, bicyclists and pedestrians, have a 20 mph speed limit.

Whitaker’s relatives could not be reached.

Adams’s brother, Quentin Adams, said the family grew up in Northeast Washington’s Riggs Park neighborhood. Waldon Adams attended Coolidge High School and did a brief stint in the Navy before falling on hard times. He dropped out of college.

Quentin Adams said his brother largely remained out of contact with his family.

In a 2015 profile on WAMU, Adams recounted what the author described as a “roller-coaster life” — suffering from asthma, hooked on cocaine at age 21 and later alcohol, diagnosed with AIDS and nearly losing his left hand in a dynamite explosion. He lived on the street for nearly 30 years, with respites at St. Elizabeths psychiatric hospital, where he started to run by circling his bed for 40 minutes a day.

Adams got help through Miriam’s Kitchen and Pathways to Housing, which helped find him a residence about 12 years ago. He continued to run and soon was completing marathons before he was sidelined with a back injury five years ago. He recently had surgery and was walking with a cane when he was hit on Saturday.

Quentin Adams said he last saw his brother a week before he was killed. Quentin Adams said he met Whitaker when she joined the brothers to watch a movie a week before they were killed.

Pathways to Housing hired Waldon Adams in 2015. In a video for the group, Adams said he had what he called “lived experience,” allowing him to connect with others living on the street.

“He told them that being homeless was not their failing,” Respress said. “He told them, ‘It is a failing of a system that was not set up to serve you.’ ”

Though he was employed part time, he worked full-time hours and was constantly on his phone to officials advocating for a client or taking Zoom meetings from bed while recovering from surgery.

“He was fierce and he was relentless,” Respress said. “He moved every mountain to get people into housing.”

Bowser appointed Adams in 2018 as one of four constituent representatives to the D.C. Interagency Council on Homelessness, which includes the city administrator, the health director, the police chief and many others.

Respress described him as an advocate who “was a hope and inspiration for people on the street. He would tell them: ‘I did it. You can do it. We can do this together.’ ”

Luz Lazo contributed to this report.