RUSKIN -- One person is feared dead after falling into what officials are calling a "ground collapse" in Hillsborough County.
The incident happened at the South County Waste Water Treatment Plant, l520 TECO Road in Ruskin.
Hillsborough Fire & Rescue responded to the scene for a rescue operation that has likely turned into a recovery effort.
Officials say the victim was walking along a pipeline when the ground gave way. Another person was with the victim and grabbed the victim's hand, but had to let go.
Officials say the victim could still be in an air pocket.
Officials had to close northbound and southbound Interstate 75 between Big Bend Road and State Road 674 to accommodate the equipment needed for the rescue. I-75 was reopened Thursday night.
Officials said the treatment plant is under construction for an $80 million expansion.