LARGO — Firefighters responded to a sinkhole that was discovered Friday in the parking lot of the Largo Mall at the intersection of Ulmerton Road and Seminole Boulevard, authorities said. The sinkhole was a trough about 10 feet long and several feet wide, Largo Fire Chief Mike Wallace said. However, it was only visible through a hole about three feet wide in the pavement. Wallace said nobody was injured or fell into the sinkhole, which was barricaded for safety purposes. Property managers were on the scene deciding how to make repairs, he said.