POLK COUNTY, Fla. — An investigation is examining potential issues with the repairs to the massive sinkhole that opened at the gypsum stack at Mosaic's New Wales phosphate mining facility in August 2016. 

Officials are investigating a potential tear in its lining at the gypsum stack at facility.

Mosaic was alerted to the possible tear by a warning system. It detected a change in water pressure within the gypsum stack.

The Florida Department of Environmental Protection has been notified.

In 2016, a sinkhole 45 feet wide and 220 feet deep was discovered beneath the stack. 

Two years later, after thousands of work repair hours and $84 million in costs, Mosaic announced the sinkhole was repaired.