News Actions Facebook Tweet Email PHOTOS: Massive sinkhole at Mosaic facility Prev Next By: WFTS Webteam Posted at 12:46 PM, Sep 21, 2016 and last updated 2016-09-21 12:46:46-04 Officials say a massive sinkhole was discovered August 27th in one of the Gypsum Stacks containment ponds. WFTS Report a typo Sign up for the Morning Headlines Newsletter and receive up to date information. now signed up to receive the Morning Headlines Newsletter. Click here to manage all Newsletters Local News & Weather. Watch Live and Free 24/7.