The deadly Legionnaires’ outbreak gripping Harlem has city officials in hot water — as locals accused them Friday of dropping the ball on life-saving inspections and needlessly slow-walking revealing exactly where the disease hit.

A fourth person has died in connection with a Legionnaires’ disease outbreak in New York City. Health officials disclosed the latest death Thursday as they revealed that some cooling towers tested positive for the bacteria in some city-run buildings.

The health department offered five ZIP codes in central Harlem -- 10027, 10030, 10035, 10037, 10039 – that were at the center of the cluster, as officials stressed the disease was airborne and could reach people even outside of the directly affected buildings.

In the five ZIP codes affected by the outbreak, the number of inspections fell more dramatically than in the rest of the city.

What are the symptoms of this type of pneumonia, called Legionnaires' disease, and how do you treat it? Here's what you need to know.