Grave Digger's greatest and last act before flipping over during the freestyle competition at the 2009 Monster Jam at the Alamodome in San Antonio on Jan 11. Most of the trucks were driven to the breaking point as they jumped off, bounced on, and drove over the obstacles made of dirt mounds, buses and crushed cars. Approximately 45,000 people attend the event. These monster trucks have big block supercharged racing V-8 engines that churn out more than 1,400 horsepower. They weigh approximately 10,000 lbs and are equipped with four-wheel steering. The wheels and tires are 66" tall and weigh 750 lbs.