McDonald’s will start selling Quarter Pounders again at all of its US locations after temporarily halting sales following an E. coli outbreak that has so far sickened 75 people in 13 states, including 13 hospitalizations and one death. The fast-food chain determined that the cause of the outbreak was onions from a facility in Colorado that were only used on Quarter Pounders, and E. coli was not present in the beef used in the burgers.

“The problem appears to be limited to a specific ingredient and a specific geography, and we remain very confident that any contaminated product related to this outbreak has been removed from our supply chain and is no longer in all McDonald’s restaurants,” McDonald’s North America Chief Supply Chain Officer Cesar Piña said in a statement posted online.

“That said, health officials noted that with increased awareness, more people will seek medical attention and the number of cases will increase.” up he continued. “This awareness is a good thing because it can lead people to be vigilant and connect with medical professionals.”

McDonald’s stopped selling Quarter Pounders in Colorado, Kansas, Utah, Wyoming, as well as parts of Idaho, Iowa, Missouri, Montana, Nebraska, Nevada, New Mexico and Oklahoma, according to the data. CDC. But all of those states will see Quarter Pounders again this week, albeit without the silver onions sourced from Taylor Farms. It’s unclear when the restaurant chain may receive onions for Quarter Pounders again.

The timing of the launch will be “on an ongoing basis,” as the restaurant explained, “based on delivery and replenishment operations.”

Most people recover from E. coli illness within 5-7 days, but others can develop serious kidney problems, including hemolytic uremic syndrome. Children, the elderly, and those with weakened immune systems are at greatest risk of getting sick from E. coli. and lawsuits from people who got sick have already started.

McDonald’s president Joe Erlinger launched a video message Sunday to apologize and reassure customers that its food is safe to eat.

“On behalf of the McDonald’s system, I want you to hear from me, we’re sorry,” Erlinger said. “For those affected customers, you have my commitment that, driven by our values: we will make this right.”

“As we move forward, I want to assure you that customers can continue to count on McDonald’s to ALWAYS do the right thing,” Erlinger continued. “Doing the right thing will show itself in different ways – big and small, public and private.”

Competing restaurants such as Taco Bell, Burger King, KFC and Pizza Hut all pulled onions from some locations last week, which came from Taylor Farms.

“The FDA is continuing its investigation of the Taylor Farms facility in Colorado Springs,” McDonald’s said in a statement. “As a reminder, McDonald’s removed cut onions from this facility from our supply chain on October 22 and said we have decided to indefinitely stop sourcing onions from the Taylor Farms facility in Colorado Springs.”