DETROIT — Steve Utash had driven the same streets through this city for years on the way to his tree trimming jobs or his home in the suburbs. But one afternoon this month, along this familiar route, he found a side of Detroit he had never encountered, a Detroit where racial tension, churning just below the surface, can break into lawlessness in broad daylight. He found a side where people sometimes talk about meting out justice on their own, mostly because they say they cannot be sure when, or if, the police will show up.

As Mr. Utash drove his pickup truck on the city’s East Side, a 10-year-old boy suddenly stepped into the street, the authorities said, and Mr. Utash’s truck hit him. Mr. Utash pulled over to check on the boy, whose leg was broken and whose mouth was bleeding. Soon after, a crowd descended on Mr. Utash, 54, beating and kicking him until he lost consciousness and was left in critical condition. That Mr. Utash is white and the crowd African-American is only part of a broader, more complicated problem of crime and violence in a largely segregated metropolitan area. As church and civic leaders condemned the attack and some in the neighborhood stepped forward to identify those involved, Detroit began searching its soul to repair the damage.

“It’s just like everybody’s mad here in Detroit,” said Corey Gilchrist, a community activist who lives near where the episode occurred and called it “a triple loss” for the young injured boy; five young men, including a juvenile, now charged in the beating; and Mr. Utash, who remains in a hospital, still not fully coherent, his family said. If one afternoon could help explain the size of the challenges facing this bankrupt city — a task that turns out to require more than just shedding a mountain of debt — it may well be the story of Steve Utash.