Hantavirus is a deadly airborne disease spread by rodent droppings. Officials believe tent cabins at Yosemite were infested with mice.
Another case of hantavirus has been detected in Texas.
In Colorado, a 7-year-old girl is recovering from bubonic plague which had supposedly been wiped out centuries ago.
A spokesperson for Butternut Street Properties refused to comment other than to say the company had hired an exterminator to address the problem.
Deputy Director of Codes Enforcement, Corey Driscoll says the owners had been cited last February for exposed trash inside the building.
Driscoll says if one of the tenants lodges a complaint, she will send inspectors to the building. She says her department has issued a number of citations each year for rodent infestations.