“He carried that flag higher and bolder than anyone,” Mr. Alva said as he stood in a wide alleyway next to the warehouse. “He skates with me today.”

More than 30 years of skating the homemade ramps and rutted streets of New York City left plenty of marks on Mr. Kessler, including scrapes and scars from bone-shattering collisions. And in many ways, Mr. Kessler left an equally strong impression on the city.

Image A makeshift memorial for Mr. Kessler. Credit... Ashley Gilbertson for The New York Times

They called him the Godfather, and as a teenager on the Upper West Side in the 1970s he skated at places with names like the Death Bowl, an abandoned pool in the Bronx, and Suicide Hill, a steep slope near the banks of the Hudson River. He also became a member of a group of graffiti writers and skaters who called themselves the Soul Artists of Zoo York and who helped define East Coast skating.

“Andy was like the president, the king,” said an artist called Zephyr, who was part of the group.

As a teenager Mr. Kessler skated on the fringes of the city, using planks pilfered from construction sites to create makeshift ramps. Later, after wrangling with the New York City parks department, he designed and helped build one of the city’s first sanctioned skate parks, at 108th Street and Riverside Drive. It opened in the mid-1990s at a spot where he had first skated 20 years before. Other skate parks followed.