Officials are still determining what caused a massive sinkhole that was discovered Wednesday morning at the Louisville Zoo.
The zoo closed after the sinkhole was discovered around 8:30 a.m. near the park’s southwest corner, far from any animal exhibits. No animals or people were injured.
Officials estimated the sinkhole is about 50 yards wide and 85 yards long and possibly 50 feet deep – almost the size of a football field! But it’s “potentially larger or deeper” in some areas.
Officials had already closed the nearby Louisville Mega Cavern due to a 3.4 magnitude earthquake reported Tuesday about 33 miles northeast of Knoxville, Tennessee. It’s the cavern’s standard procedure to close if seismic activity is detected, said Charles Park, the cavern’s executive vice president.
Cause of ground collapse remains unknown
An engineer who inspected the area does not believe the sinkhole was caused by the earthquake because of the timing, Louisville Metro Emergency Services Director Jody Meiman said. The earthquake was reported around 4 p.m. Tuesday and officials believe the sinkhole formed between late Tuesday and early Wednesday morning.
Meiman said the sinkhole could have been caused by rain runoff or “natural occurrences” underground, but officials were still working to determine what happened.
Late Wednesday, engineers were evaluating whether the sinkhole could continue to grow. Geotechnical and mining engineers were on site, as well as officials from Louisville Water, Metropolitan Sewer District, Louisville Fire and Louisville Gas & Electric.
Sinkhole location and safety
Meiman said that the sinkhole is near the edge of the cavern and that some debris fell into an unoccupied section of the cavern. Crews will continue inspecting that part, which is under the zoo, through the night.
But the nearby commercial and residential areas have been deemed safe, Meiman said. Crews monitoring utility lines had not noticed “any adverse effects” or danger to neighbors in the area, who had been notified of the sinkhole.
The zoo and the Louisville Mega Cavern will remained closed until further inspection deems them safe.
“Right now, our priority is safety,” Louisville Zoo Director John Walczak said. “So we’re going to let all the engineers do their work, and we’ll make that determination (to open) when they say it’s safe.“