Chipotle to Close All Stores for One Day in February The company's sales plunged 30 percent in December, following at least six outbreaks tied to Chipotle in the last year, including norovirus, E. coli and salmonella.

The company's sales plunged 30 percent in December, following at least six outbreaks tied to Chipotle in the last year, including norovirus, E. coli and salmonella.

At least nine lawsuits have been filed, according to The Chicago Tribune. And more suits are coming, says Bill Marler, a food and safety litigator in Seattle.

"I represent a total of 75 people, but I haven't filed all their lawsuits yet," he told the Tribune.

At an investment conference in Orlando, Fla., on Wednesday, Chipotle executives said the company is taking measures to reduce the risk of another food scare to "near zero."

The company will start "inviting customers back" to restaurants in February with increased marketing and direct mail offers.

Chipotle Chief Financial Officer Jack Hartung noted the company's recovery would be "messy," with investments in food safety and marketing eating into profit margins.

Chipotle Mexican Grill Inc., which is based in Denver and has more than 1,900 locations, said it has already made many changes to tighten its food safety. The steps include moving the chopping of tomatoes and lettuce to a centralized location, and blanching onions to kill germs before they're chopped.

Executives said they expect the Centers for Disease Control and Prevention to declare the E. coli outbreak to be over at some point. The agency has not identified an ingredient that was responsible for the E. coli outbreak, and Chipotle has said it may never know what was to blame.

The Associated Press contributed to this report.