Louisville Mega Cavern closed following earthquake in Tennessee

LOUISVILLE, Ky. (WDRB) -- A Tennessee earthquake forced the temporary closure of the Louisville Mega Cavern.

The news of the closure came before the announcement that a sinkhole had formed on the grounds of the Louisville Zoo. The Mega Cavern sits under part of the zoo. It is too early to say whether the seismic activity is connected to the development of the sinkhole.

A 3.4 earthquake was recorded on Tuesday afternoon near Knoxville near Maynardville, Tennessee. The United States Geological Survey says the quake was felt in Kentucky.

In a release, the Louisville Mega Cavern says out of caution, they are closed Wednesday. "Our mine engineers will be inspecting the cavern out of an abundance of caution for the general public and our tenants." said Charles Park, the executive vice president of the facility. He says the Mega Cavern established the policy in 2012, when the last earthquake in the region was reported.

The USGS says a 3.4 earthquake can be felt by people who are indoors -- especially on upper floors of buildings. Vibrations are similar to the passing of a truck.

Knoxville does not sit along a fault line, but it is in the East Tennessee Seismic Zone. Parts of western Kentucky and southern Illinois do sit on the New Madrid fault line, which is the most active seismic zone east of the Rocky Mountains.

Once engineers have given the all clear, the facility will reopen. Louisville Mega Cavern apologized to its customers and tourists and offered full refunds for any cancelled events.

The 100-acre limestone cavern and its 17 miles of underground passageways is used for storage and entertainment including zip lines, rope and bike courses and a tram tour.