AIG Building Palm Harbor, Florida Geotechnical: CFTL Clearwater, Florida Structural: BILL PAXTON Tampa, Florida This building was under construction and about to be finished when a sinkhole depression opened up near the back corner of this structure. The sinkhole developed when a well driller was setting the casing for an irrigation well. The well casing had punched into a subsurface cavern and triggered a small collapse. CFI injected 130 cubic yards of grout to help fill the subsurface cavity. Following the pressure grouting program 8 underpins were installed to help secure the corner of the building.