The FBI has renewed its search for Leo Frederick Burt, a 22-year-old University of Wisconsin student who remains at large following the deadly bombing of Sterling Hall on August 24, 1970. Burt is currently listed among the FBI's top ten most wanted domestic terror fugitives. The incident, which occurred in Madison, Wisconsin, involved the detonation of one ton of ANFO explosive hidden in a stolen Ford Econoline van parked outside the Army Mathematics Research Center. The blast killed post-doctoral researcher Robert Fassnacht, 33, and caused significant damage to the university building. While three other individuals involved in the attack were arrested, prosecuted, and convicted, Burt successfully evaded capture for 56 years. Authorities have released an age-progressed image of Burt, estimating his current appearance at approximately 75 years old, and have offered a $150,000 reward for information leading to his capture. The investigation is being handled by the FBI, which continues to seek public assistance in locating the long-elusive suspect. The case remains one of the most prominent unsolved domestic terrorism incidents in U.S. history, with Burt's status as a fugitive unchanged despite decades of law enforcement efforts.