After an E. coli outbreak linked to McDonald’s quarter pounder hamburgers sickened 49 people and killed one person, the company’s president said on Wednesday he was confident customers could come into the restaurant without falling ill.

McDonald’s USA President Joe Erlinger addressed the outbreak on TODAY on Oct. 23.

“We are very confident that you can go to McDonald’s and enjoy our classics,” Erlinger said. “We took swift action yesterday to remove the Quarter Pounder from our menu.”

The Centers for Disease Control and Prevention announced on Oct. 22 it was opening an investigation into a “severe” E. coli outbreak linked to McDonald’s quarter pounders across 10 states.

It is unclear which ingredient in the burger is contaminated, the CDC said. McDonald’s has stopped serving quarter pounder beef patties and slivered onions in several states, according to the CDC.

Erlinger said two ingredients are being investigated, and that the Quarter Pounder has been removed from menus in some states.

“This was swift and decisive action by us, and it is the quarter pounder and two ingredients on that quarter pounder that are under investigation by the CDC,” he said. “So I want to say to our consumers that you can confidently go to McDonald’s today.”

The company is working closely with its supplier and the CDC, Erlinger said.

“Food safety is our top priority at McDonald’s, it’s the top priority in this building where I am, at the McDonald’s headquarters. It’s a top priority in our nearly 14,000 McDonald’s restaurants across the U.S. It’s the top priority for our suppliers as well,” Erlinger said.

“This is something that we talk about as being everyone’s business. And so while the investigation continues, and we’ll continue to get into the details of those investigations, I don’t think that’s what’s important,” he continued. “What’s important today is that we’ve taken the action to protect the American public and promote public health.”

The CDC said there have been 49 cases linked to the outbreak from Sept. 27 to Oct. 11, leading to 10 hospitalizations and one death.

“This outbreak may not be limited to the states with known illnesses, and the true number of sick people is likely much higher than the number reported,” the CDC said.

The affected states are Oregon, Utah, Montana, Wyoming, Colorado, Nebraska, Kansas, Iowa, Missouri and Wisconsin, according to the CDC.

Erlinger said the company will rely on the CDC to continue the investigation and trace the outbreak.

“It is important to note that the onset dates for this disease are between, at this point, Sept. 27 and Oct. 11. If there has been contaminated product within our supply chain, it’s very likely worked itself through that supply chain already,” he said. “But certainly we will be working with the CDC and cooperating with them on the investigation, and we’ll take in more data and let the science continue to lead our actions.”

When asked how worried he is about the outbreak keeping customers from returning to McDonald’s, Erlinger quoted Ray Kroc, who purchased McDonald’s in 1961.

“Our founder famously said, ‘If you take care of our customers, the business will take care of itself.’ And so on a day like today, given the news we’ve had over the last 24 hours, that’s really our focus,” Erlinger said. “We’re confident that we’ll see our way through this, and we’ll restore confidence for the American consumer to come to McDonald’s.”