McDonald’s was sued on Tuesday by consumers in a proposed class action stemming from the E.coli outbreak linked to onions in the fast-food chain’s Quarter Pounders.

Amanda McCray of Chicago and William Michael Kraft of Davie, Florida, said they experienced many symptoms associated with E.coli infection after buying Quarter Pounders this month.

Both said they would not have bought their burgers had McDonald’s disclosed the risk of contamination, and have suffered damages because of McDonald’s actions.

The lawsuit filed in Chicago federal court seeks unspecified damages, but exceeding $5 million, for all people in the United States who bought Quarter Pounders contaminated with E.coli.

McDonald’s did not immediately respond to a request for comment. The chain also faces other lawsuits by individuals who said they were also sickened.

Last week, McDonald’s halted Quarter Pounder sales in one-fifth of its 14,000 U.S. restaurants after an outbreak that killed at least one person and sickened 75 people.

The Chicago-based company began restoring Quarter Pounders to its menus this week.

After McDonald’s reported quarterly results on Tuesday, Chief Executive Chris Kempczinski apologized to customers for the outbreak. He said on a conference call that the situation appeared contained, and that he was “confident in the safety of eating at McDonald’s.”

The case is McCray et al v McDonald’s USA LLC, U.S. District Court, Northern District of Illinois, No. 24-11102.