We all fall down / Michael Harvey.

Enhanced descriptions from Syndetics:

Chicago cop turned private investigator Michael Kelly is racing to save his city from a deadly new foe: a biological weapon unleashed underground.

When a lightbulb falls in a subway tunnel, it releases a pathogen that could kill millions. While the mayor postures, people begin to die, especially on the city's grim West Side. Hospitals become morgues. L trains are converted into rolling hearses. Finally, the government acts, sealing off entire sections of the city--but are they keeping people out or in? Meanwhile, Michael Kelly's hunt for the people who poisoned his city takes him into the tangled underworld of Chicago's West Side gangs and the even more frightening world of black biology--an elite discipline emerging from the nation's premier labs, where scientists play God and will stop at nothing to preserve their secrecy.

It's a brave new world . . . and the most audacious page-turner yet from an emerging modern master.