BALTIMORE — In good times, DeAndre McCullough inspired nearly everyone he touched. He was a small-time drug dealer made good, a recovering addict who had a fledgling career counseling troubled teenagers. He played bit roles on HBO in The Wire and in the miniseries The Corner, which chronicled his life in the drug trade at the age of 15.

He had survived the inner-city whirlpools that swallowed so many people he knew. His father and several friends lost their lives to drug overdoses or gunfire. McCullough, who abused cocaine and heroin, never expected to live past 20.

“I’m 35 today,” he marveled in a text message that he sent to his mentor, David Simon, the acclaimed writer and television producer, in May. “Never thought I’d make it. How ‘bout that?”

But last month, McCullough was found dead from heroin intoxication, making him a powerful symbol of the urban maelstrom that has devoured so many young men. To the people who knew him, his demise was all the more heartbreaking because a better life had seemed so tantalizingly within his reach.

Michael Potts, the actor who played Brother Mouzone on The Wire, heard the news just as he was about to step on stage to perform in The Book of Mormon on Broadway. McCullough had played Mouzone’s sidekick, Lamar.

“I was devastated,” said Potts, who said he had to steady himself for his performance. “As an African-American man, I thought: ‘Oh my God, I’m losing another one, not another one.’”

Here in Baltimore, friends and relatives had hoped he would avoid this all-too-familiar fate. Of McCullough’s closest teenage buddies, three ended up dead, four ended up in prison, and several ended up addicted to drugs.

“Once The Wire and everything hit, I thought life was going to be good for DeAndre,” said Kevin Thomas, the only one of McCullough’s close male friends to graduate from college.

Thomas, who works for a real estate company, knows how drugs and violence can burn through a family. His father died of a drug overdose. His mother, who was also an addict, died from AIDS. His brother was shot to death leaving a nightclub.

He had hoped that McCullough, his best friend from third grade, would be spared.

“To see him go down that road of self-destruction was heartbreaking,” he said.

He still remembers McCullough as a teenager, laughing and joking on Fayette and Mount streets, a drug-infested street corner in an impoverished community. The son of two drug addicts, McCullough sold drugs, skipped school and rarely read books.

Yet McCullough also wrote poetry. He was familiar with Machiavelli’s “The Prince” and he had a wry sense of his place in a warped world.

Ed Burns, who with Simon wrote the book The Corner: A Year in the Life of an Inner-City Neighborhood, which inspired the HBO miniseries, said McCullough stood apart.

“He seemed to know a lot of what the world was about,” he said. “He could articulate the injustice, which was all around him. The other kids couldn’t. They suffered it, but they weren’t conscious of it. He was conscious of it.”

The book, published in 1997, opened new possibilities. Suddenly, McCullough was being interviewed on Nightline on ABC and on NPR. He was 20 and thinking there might be another way of living.

“This is what I’ve done my whole life,” McCullough told NPR in 1998, describing his years of dealing and abusing drugs. “It defined me as a person. And now I’m trying to define myself as someone else that I’ve never been.”

He enrolled in drug-rehabilitation clinics and tried to get clean. He got his GED and went to community college for a semester with help from Simon and Burns.

He found honest work at a furniture store and a hospital, and at security companies. And he played bit roles in Simon’s productions.

In The Corner, he played the policeman who arrests the character based on his life. In The Wire, he took on the role of the assistant to Brother Mouzone, a drug enforcer.

But it was at Mountain Manor Treatment Center where he found his niche. He spent about two years there, counseling young drug addicts, and dreamed of opening a youth center of his own.

“Oh my God, he just had a gift,” said Charlotte Wilson, a counselor who worked with him in 2004 and 2005. “He could share the pain and he could share the joy. He would read the kids his poetry about living life on the street, hard knocks, talking about drugs and how you can come up out of it. They loved him.”

His mother, Fran Boyd Andrews, who overcame her own addiction, said it was the longest time he would stay sober.

“I think that was the happiest I ever seen my son,” she said.

But no matter what McCullough did, the cravings kept creeping back. He started missing work and finally his supervisor let him go.

Over the next seven years, he drifted from one low-wage job to another, in and out of drug-rehabilitation clinics, and he spent long stretches unemployed.

His relatives, friends and two young sons prayed for him and helped whenever they could. But he couldn’t escape the pain within himself, the gnawing sense that he would never succeed.

“It just ate at him and ate at him,” his mother said, “until he couldn’t get a grip on it.”

Last fall, he turned to Simon again, pleading for work on the set of Treme in New Orleans.

“He said, ‘I’ll get clean. I’ll do whatever I have to do,’” Simon recalled. “There was a weariness and a fear in his voice that convinced me that we had to try.”

Simon offered him a position on the set’s security team. McCullough started in October. By January, he was out of a job.

“There are corners here, too,” he told Simon.

“What was the trigger that sent him back to addiction?” Simon asked. “It’s the biggest question in the world.

“But the journey from one America to the other is epic,” he said. “Once you’ve become a citizen of one, it’s really hard to find citizenship in the other.”

Back home in Baltimore, McCullough couldn’t find work. By June, the police said, he had found another way to fuel his drug habit.

“My heart nearly fell to my feet,” Boyd Andrews said of the moment that she saw a crime scene photo that the police had posted online.

The authorities said it was her son, who was accused of robbing two pharmacies and fleeing with bottles of morphine and oxycodone.

McCullough promised to turn himself in once he was clean, and he enrolled in another drug clinic. But two weeks before the program was over, he checked himself out.

“I knew then that he was back at it,” his mother said.

On the day before the police found his body, McCullough was hopeful. He had a line on a landscaping job and was talking about getting back on his feet.

The next morning, McCullough, who always called his mother at 8 a.m., didn’t call. That evening, a cousin went to his house and found him lying dead in the bathroom. His addiction had finally swallowed him whole.