Officials are investigating whether Tuesday’s earthquake in Maynardville opened a massive sinkhole inside the Louisville, Kentucky, Zoo.

The hole was discovered in an undeveloped area of the zoo. Officials said no animals were injured and there was no damage to any buildings.

A zoo spokesperson said engineers are on site, investigating.

As part of standard procedure, following the Tennessee earthquake, the Mega Cavern, an old limestone mine open to tourists in Louisville, Kentucky, closed.

“Earthquakes happen. This is a natural event. It is the Louisville Mega Cavern’s standard customary practice to close the cavern in the event of an earthquake,” said Louisville Mega Cavern Executive Vice President Charles Park. “Our mine engineers will be inspecting the cavern out of an abundance of caution for the general public and our tenants.”

This post-temblor closure was established as the cavern’s standard procedure in 2012, when the last earthquake in that area was reported. As soon as the attraction’s mining engineers give the all clear, the cavern will resume normal business operations.