You all remember the incident where U.S. pilots accidental bombed and killed some Canadian soldiers who where training in Afganistan.....?? Accidental bombing killed four September 13, 2002 Posted: 2:13 PM EDT (1813 GMT) From Barbara Starr CNN Washington WASHINGTON (CNN) -- Citing a "fundamental lack of flight discipline," the Air Force Friday charged two Illinois Air National Guard pilots with involuntary manslaughter and assault for their role in the fatal accidental bombing of Canadian soldiers in Afghanistan this past spring. The April 17 incident killed four Canadians and wounded eight others. F-16 pilots Maj. Harry Schmidt and Maj. William Umbach were each charged with four counts of involuntary manslaughter and eight counts of assault. Schmidt was also charged with failing to exercise appropriate flight discipline and not complying with the rules of engagement in Afghanistan. Schmidt was flying the plane which dropped a 500-pound bomb on a group of Canadian soldiers conducting a nighttime training exercise in southern Afghanistan. The pilot said he believed he was bombing an enemy ground position and mistook the training fire for enemy action. Schmidt said he fired in self-defense, but the investigation centered around whether he was given permission to fire on the target. Umbach, the flight leader who was piloting another plane, was also charged with four counts of involuntary manslaughter and eight counts of assault. Investigators believe that as lead pilot, he should have stopped Schmidt from dropping his bomb before controllers gave approval to engage the target. Umbach was also charged with failing to exercise appropriate flight command and control and to ensure compliance with rules of engagement. The charges come after a recommendation from Air Force investigators looking into the incident. A final report on the bombing was released by both the Pentagon and the Canadian government. "Both pilots ... demonstrated poor airmanship and judgment and a fundamental lack of flight discipline throughout the course of the incident," read the report, which also cited "poor planning and preparation combined with problems with attention, misperception and fatigue." The pilots could now face an Article 32 proceeding under the Uniform Code of Military Justice. That is similar to a grand jury proceeding and the results could send them to a court martial.