The lawsuits, filed in Milwaukee County Circuit Court Thursday, seek damages for pain and suffering and punitive damages from meat company Excel Corp.
More than 60 people got sick and a 3-year-old South Milwaukee girl died after eating at the restaurants in July 2000. Health officials believe the patrons got sick after eating foods that somehow became contaminated by the bacteria from the meat.
Investigators blamed Sizzler's meat handling procedures for the contamination.
The filings represent another chapter in a long legal battle.
Milwaukee County Judge Michael Sullivan ruled in May 2002 that Excel couldn't be sued for supplying the beef to Sizzler restaurants in Milwaukee and Wauwatosa. Excel's attorneys had argued the company wasn't liable because it didn't mishandle the meat and complied with U.S. Department of Agriculture inspections before shipping.
But a state appeals court overturned that ruling a year later, saying even though federal authorities inspected the meat, the processor still had to make sure it was safe. The court reinstated 14 lawsuits against Excel.
Excel appealed to the U.S. Supreme Court, but the court refused to hear the appeal, clearing the way for the lawsuits.
"It is time for the company to take responsibility for its actions and compensate victims of its negligence," said William Marler, managing partner of law firm Marler Clark, which is representing the children.
Excel spokesman Mark Klein said there's still questions about the source of the E. coli contamination.
"People got sick from eating at the salad bar, not from eating meat," Klein said.