While imprisoned for having taken part in a nonviolent protest, Dr. King wrote the now famous Letter from Birmingham Jail, a defining treatise in his cause against segregation. Birmingham is also known for a bombing which occurred later that year, in which four black girls were killed by a bomb planted at the 16th Street Baptist Church. The event would inspire the African-American poet Dudley Randall's opus, "The Ballad of Birmingham", as well as jazz musician John Coltrane's song "Alabama".