Update: Texas peanut plant closes in connection with salmonella outbreak

A review of the national salmonella outbreak is focusing on who allowed tainted peanut products to contaminate hundreds of other foods.

A hearing is planned tomorrow in Washington before the U.S. House Energy and Commerce investigations subcommittee.

Michigan Congressman Bart Stupak, who chairs the panel, wants to know how Peanut Corp. of America shipped allegedly tainted goods month after month -- without regulatory intervention.

Federal law forbids producing or shipping foods under conditions that could harm the health of consumers.

Peanut Corp.'s troubles mounted this week as the FBI raided its Georgia plant. Its peanut processing unit in Plainview, Texas, is also shut down.

The company has said it is still investigating what happened and has expressed regret and concern for people who became ill.