After suddenly suffering a cerebral thrombosis, Costa e Silva was removed from duties on August 31, 1969. Although civilian Vice President Pedro Aleixo should have succeeded him, the three armed forces ministers instead took power as a military junta under the 12th Institutional Act. Costa e Silva legally remained President until October 14, when he was formally removed from office by the 16th Institutional Act. Costa e Silva died on December 17 of that same year, the victim of a heart attack.