Popular fast food chain In-N-Out Burger voluntarily closed its Livermore, California location Tuesday night after it was reported that some customers had fallen ill after eating there.

The restaurant at 1881 North Livermore  Avenue remained closed for the day Wednesday after nine members of a college softball team ate at the popular burger joint and were reported to have become sick, possibly with a norovirus, health officials were reported saying by SFGate.

“Here at In-N-Out Burger, the health and well-being of our customers and our associates is a top priority,” In-N-Out Vice President of Operations, Denny Warnick said in a statement to Fox affiliate KTVU. “We apologize for any inconvenience this closure may cause for our customers and we will re-open our Livermore restaurant once we are certain that there are no issues there.”

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SFGate however reported Warnick saying the company’s investigation “did not turn up any indication that there were any issues at our restaurant.”

The nine patrons affected dined at the restaurant Saturday and developed flu-like symptoms soon after. The restaurant did not open Wednesday so workers could clean and disinfect the location and ensure the staff was screened for pathogens.

Tourists and regulars who were looking forward to their burgers Wednesday were in for a disappointment as they were met with traffic cones blocking the entry to the parking lot.

“We heard a lot about it from our Californian relatives that we should try In-N-Out Burger, so we saw one, and now I’m a bit worried as to why it’s closed,” Raymond Kennedy, a tourist from the United Kingdom, told ABC7.

The restaurant has requested customers to stay away until the company issues a further notice.

“This is one of my regular stops on the way to LA and I can eat it in the car and hurry up and get down, so yeah I was shocked,” another customer Velma Horn-Cantrell of American Canyon told the network.

However, the regulars will not stay away from In-N-Out for long.  Customers said they’ll be back once the restaurant is ready. Concord, California resident George Croitor said, “Yes, In-N-Out is one of my favorite restaurants.”

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Livermore’s mayor John Marchand praised In-N-Out for its quick action in dealing with the issue and also called the fast food chain a terrific community partner. He was quoted by ABC7 as saying, “They know how popular this is, so if there's any question in their mind, they want to make sure that no one, no individual's going to be put at risk.”

First opened in Baldwin Park, California in 1948 by Harry and Esther Snyder, the company was inherited by their granddaughter Lynsi Snyder seven years ago.

While she inherited 50 percent of In-N-Out’s shares when she turned 30, Snyder acquired the remaining shares earlier this month when she turned 35, making her one of the youngest female billionaires in the country.