Four residents of a veteran’s home in Illinois are dead after an outbreak of Legionnaires’ Disease.

At least 29 other residents of the Illinois Soldiers and Sailors Home have been infected with the deadly bacterium.  Those who died allegedly had severe underlying medical conditions that compromised their immune systems and left them particularly vulnerable to the bacteria.

“The Legionella bacteria can be found anywhere, but it’s usually in small doses that won’t make you sick,” Adams County Health Department Director of Clinical and Environmental Services Shay Drummond told WGEM-TV. “But when a cluster of people get sick like this, it’s very likely there’s one source point.”

Drummond believes the outbreak has been contained to just the veteran’s home.

At San Quentin State Prison in California, six inmates have been confirmed to have the disease with another 51 under observation in the prison’s medical unit.

Prison officials say all cooking at the prison has been shut down and that prisoners are eating box meals until the source of the disease can be found.

In New York City, where 12 people died from an outbreak this summer, a school had to be shut down after the bacteria was found in a cooling tower.  City officials praised the school’s quick response and also said the action showed the importance of a new city law designed to combat the disease.

“The Convent of the Sacred Heart School properly disinfected its cooling tower. Its cooling tower’s positive test result, and subsequent disinfection, underscores the importance of the new legislation the Mayor signed just two weeks ago,” the Department of Health said in a statement.