HONG KONG—Life in Hong Kong was crippled for a third straight day Wednesday, as the aftermath of two days of violence and fears of further clashes disrupted transportation and kept many children home from school.

Commuters struggled to get to work. Dozens of bus lines were suspended, subway service was delayed and several train stations were either closed or offered limited access. Huge crowds piled up in the subways amid the long delays. Streets, meanwhile, were filled with bricks, poles, garbage—the debris of another night...