Modern M1A2 tanks are tough critters to knock out. Can be done, but it takes a lot.

One of my brothers-in-law was a track commander in the 11th Cavalry in Vietnam. He said maneuvering in the bush was not easy, even in the smaller M113 APCs. Charlie could get pretty close to them. His track got hit with several RPGs at once and literally blew him out of the TC's hatch like a cork. He was the only survivor out of six people aboard. His injuries are really catching up to him these days.