Chipotle Mexican Grill won’t be open to serve Americans lunch Monday, because the fast-casual restaurant chain is closing its stores to implement a new food safety program.

The company’s restaurants will be shut for four hours today (from 11 A.M. to 3 P.M. local times), as Chipotle cmg management aims to train staff about changes to food prep and food handling, with a lot of attention paid to the cleaning and cutting of fresh produce and new protocols for marinating chicken and steak.

The company spelled out some of the details of its food handling changes last week when executives talked to analysts during a quarterly conference call. Chipotle intends to live tweet some of the details from its official Twitter handle @ChipotleTweets, as well as share video on the live streaming app Periscope.

Chipotle also separately warned that the sales hit from the food-borne illness incidents and efforts to win back customers via free or discounted food promotions and a big marketing push would result in Chipotle likely reporting net income at roughly break-even levels in the first quarter of 2016.

The move to close the stores comes after the chain spent a few months struggling to find a way to respond to E. coli and Norovirus outbreaks that raised damaging questions about food safety at the chain. Chipotle couldn’t come up with a firm strategy to respond to the string of updates from the Centers for Disease Control and Prevention as the E. coli case spread across several states. It even blaming the media at one point before finally having co-CEO and founder Steve Ells publicly apologize.

Last week, Chipotle’s results highlighted just how bad things have gotten. Revenue for the final quarter of 2015 slipped 6.8% to $997.5 million, with sales at existing restaurants tumbling 14.6%. Ells admitted that the quarter was “the most challenging period in Chipotle’s history,” though encouragingly, the CDC closed its investigation into the E. coli incidents associated with Chipotle.