BALTIMORE — As Omar Little, actor Michael K. Williams patrolled the streets of Baltimore with a shotgun and a terrifying swagger. But in real life, friends say the man they called “Mike” cared deeply for the city and the people in it.

Williams died Monday, New York City police said. The former “Wire” co-star was 54.

The actor hailed from Brooklyn, New York, but “Baltimore was a second home to him,” said local activist Jerel Wilson. “If anyone knows Mike, they would say the same thing.”

Wilson befriended Williams while the actor was filming the critically acclaimed HBO series, which first aired in 2002. They would grab crab cakes at Lexington Market, where Williams took notes on the way Baltimoreans spoke and dressed.

The character of Omar Little, the ruthless stickup man, was partly inspired by real-life gangster Donnie Andrews, who robbed rival dealers as a young hustler in West Baltimore.

In contrast to his intimidating on-screen demeanor, Williams was “Humble, grateful” and “very shy” in person, said Wilson. “Behind the scenes, he was down to earth and low key.”

Visiting blighted neighborhoods in East and West Baltimore while shooting “The Wire” fed Williams’ determination to make a difference in those areas. He frequently advocated on matters ranging from police reform to public health. He tackled some of these issues in the BET series “Finding Justice.”

“I want to give my energy to things that can create solutions,” he said in an episode confronting the issue of lead poisoning in Baltimore.

More recently, Wilson, who runs the organization For My Kids Inc., had been collaborating with Williams on an upcoming documentary.

Williams returned to the city this year. He passed out hugs and pep talks to neighborhood kids while promoting a store called BeMoreGreen, which he wrote in an Instagram post gives out free groceries and also sells Black-made products. “This is what rebuilding our community, and doing it ourselves, looks like,” Williams wrote.

A video shared to social media shows the actor leading a group of youngsters in a chant.

“I am — somebody,” he repeated to them. “I say that every day when I wake up.”

While Williams’ role in “The Wire” helped shoot him to fame, an important break came courtesy of another famous Baltimorean, Tupac Shakur. The rapper and Baltimore School for the Arts alum chose him to play his brother in the 1996 film "Bullet."

Even after “The Wire” ended, Williams often went out of his way to get a crab cake while passing through the area. “He loved our crab cakes, Baltimore crab cakes, that was his favorite meal in the world,” Wilson said. He also stopped by to visit friends, including former Wire co-star Felicia “Snoop” Pearson. He posted a photo of them together this spring.

———