Car plunges into 10-foot-deep sinkhole as road caves in Chennai. A portion of Rajiv Gandhi Salai (OMR) near Tidel Park in Chennai caved in on Thursday. The sudden road collapse caused a car to plunge into a 10-foot-deep sinkhole, triggering panic among motorists and disrupting traffic movement. A man and a woman were inside the car when it fell into the sinkhole, but both passengers were safe, India Today reported.