Public health officials in Seattle & King County are probing an apparent norovirus outbreak after 13 people reported falling ill after visiting a West Coast Mexican chain. The group dined on May 21 at the Mazatlan restaurant located in the Seattle suburb of Auburn, Wash. According to the health department , symptoms of the ensuing "norovirus-like illness" included body aches, chills, diarrhea, and vomiting. Officials have thus far been unable to determine how the virus was spread. Mazatlan, which started in 1968, now has 14 locations in the Pacific Northwest. RELATED: The Saddest Restaurant Closures in Your State "We have not identified how norovirus was spread within the [impacted] restaurant," the department said. "This is not uncommon for norovirus outbreaks because the virus can spread through multiple contaminated food items, environmental surfaces, and from person to person." A previous inspection apparently revealed "high-risk violat