In 1937, Albizu Campos' party organized a protest in Ponce. The Insular Police, similar to the National Guard, opened fire upon unarmed cadets and bystanders alike. The attack on unarmed protesters was reported by U.S. Congressman Vito Marcantonio and confirmed by a report from the Hays Commission, which investigated the events, led by Arthur Garfield Hays, counsel to the American Civil Liberties Union. Nineteen people were killed and over 200 were badly wounded, many shot in the back while running away. The Hays Commission declared it a massacre and police mob action, and it has since become known as the Ponce massacre. In the aftermath, on April 2, 1943, Tydings introduced another bill in Congress calling for independence for Puerto Rico, though it was again defeated.