NEW YORK (AP) — Chipotle is still giving away free burritos to convince people its food is safe and combat the eeriness of empty stores.

The Denver-based chain made its first big push with freebies on Feb. 8 when it closed stores nationwide for a few hours so employees could participate in a food safety meeting after an E. Coli outbreak and other incidents sent sales plunging.

"It was kind of eerie — and we'd hear this from customers. They would walk by a restaurant and see, god that was always busy, and now there's no line whatsoever," said Jack Hartung, Chipotle's chief financial officer, speaking Wednesday at the Bank of America Merrill Lynch Consumer and Retail Tech Conference.

Although traffic is still down, he said restaurants are looking fuller now and that the free offers are convincing people to become paying customers again.

He said it was important to let the chain's 2,000 restaurants "look like Chipotle again."

The company said 5.3 million people tried to download the mobile coupon for a free entree offered on Feb. 8 as a "rain check" for when stores were closed.

"That was our first test to see how much people really wanted to come back to Chipotle," said Mark Crumpacker, chief creative and development officer.

The company has since also started mailing people coupons for a free entree. Crumpacker said there are about 6 to 10 million such offers in circulation already, out of the 21 million the company has planned. Those all expire by around May 15, he said.

Moving into the summer, he said Chipotle might shift to "Buy One, Get One" free offers, or do more targeted mobile offers for free meals in regions of the country where a recovery in sales is lagging.

Crumpacker said the expiration dates on coupons give people that extra nudge they might need to go into a Chipotle again. Executives are also concerned about the perception customers may have when they see empty restaurants.

Chipotle had become a star on Wall Street, with its restaurants packed and its sales booming.

The strategy of giving away free burritos to get stores busy again will cost Chipotle. The company said Tuesday it expects to report a loss of $1 per share or more for the January-to-March quarter. That would mark its first loss since going public in 2006.

The loss would reflect a 36 percent sales decline at established restaurants in January, which was followed by a 26 percent drop for February, despite the extra day in the month this year. Costs, meanwhile, have spiked due to factors including the free burrito promotions, stepped up marketing and investments in food safety.

Chipotle Mexican Grill Inc. has taken a number of measures to ensure it doesn't experience another food scare. That includes no longer leaving out lemon wedges by the soda fountain and napkins for customers to take as they please; people now need to ask for them.

Its stock fell $2.65 to $500.35 on Wednesday and is down 26 percent over the past year.

___

Follow Candice Choi at www.twitter.com/candicechoi