SAN ANTONIO - TEXAS health officials have shut down a processing plant linked to contaminated celery that sickened at least six people this year, four of whom died, and ordered the recall of all of the produce that passed through the plant since January.

SanGar Produce & Processing Co issued the recall Wednesday after its plant in San Antonio was shuttered. The Texas Department of State Health Services traced six of 10 known cases of listeriosis in the state during an eight month period to celery processed there.

The agency is investigating the origins of the other four cases, which include one death.

Health inspectors found problems with sanitation at the plant, including a condensation leak over a food production area. The health department is trying to determine who the now-recalled produce was sold to and whether it was used in other products. The agency recommends that customers throw out or return all SanGar products.

The Food and Drug Administration is also looking into the contamination and may decide to expand the recall once it learns more, dont Kraemer, the deputy director in the FDA's Office of Food Safety, told The Associated Press on Thursday.

Texas health department spokesman Carrie Williams said that the state asked the company to close voluntarily but it refused. 'They refused, so we shut them down and ordered a recall,' she said.

Tainted celery kills 4 in Texas