Pharma company GlaxoSmithKline closed a plant Tuesday after the facility tested positive for Legionella bacteria during routine inspections.

The drugmaker's plant in Zebulon, N.C., was shut down when the bacteria causing Legionnaires' disease were discovered in a self-standing cooling tower. About half of the plant's 850 employees were sent home and were told not to report until further notice, Associated Press reports.

The company said the decision to close the plant was a precautionary measure. It assured the public that the medicines manufactured in the plant, which include inhaled asthma drug Advair, have not been infected with the bacteria, as the cooling tower was a self-standing structure that had no contact with the drugs, Reuters reports.

There are no employees who have shown symptoms of Legionnaires' disease so far.

"No employees are sick and no products have been compromised," GSK spokeswoman Brewer Ligday told ABC News. "Medicines were not exposed to the bacteria."

This was confirmed by North Carolina health officials, who said that there are no reported cases of Legionnaires' disease associated with GSK's Zebulon plant, according to ABC News.

The drug company said the plant will reopen as soon as the situation is remedied.

"The cooling towers will be cleaned and retested before the site goes back into operation. GSK is taking these precautions to ensure the health and safety of our employees, as well as the safety and integrity of our products," the company said in a statement, according to Reuters.

In New York City, 12 people have died from a Legionairres' outbreak. Click HERE for HNGN's coverage of the outbreak, which so far has been contained to the Bronx.