Health officials said Wednesday they are investigating an outbreak of Legionnaires’ disease, a severe and sometimes lethal form of pneumonia spread through the air, in New York City’s Bronx over the last two weeks. The city health department said two people have died and 29 other cases have been reported in the south Bronx area. The disease is caused by exposure to the bacteria Legionella, which can be inhaled through contaminated aerosols from cooling towers, hot tubs, showers, faucets, or drinking water. Patients are stricken with symptoms similar to pneumonia, including shortness of breath, high fever, chills, and chest pains. The health department urged anyone experiencing symptoms to seek immediate medical attention.