Joseph Albert "Jock" Yablonski (March 3, 1910 – December 31, 1969) was an American labor leader in the United Mine Workers in the 1950s and 1960s known for seeking reform in the union and better working conditions for miners. In 1969 he challenged Tony Boyle for the presidency of the international union and was defeated. He asked for a Department of Labor (DOL) investigation, charging a fraudulent election. In addition, Yablonski filed suit against the UMWA on five different charges related to fraud. On New Year's Eve, Yablonski, his wife and 25-year-old daughter were murdered, fatally shot at home by three gunmen found to have been hired on orders of Tony Boyle. A total of seven persons were convicted of murder and conspiracy to commit murder; two of the assassins were sentenced to death for first-degree murder. DOL completed its investigation, aided by the FBI, and won a suit to overturn the 1969 election by 1972. A new election was held in December of that year and a reform candidate elected, defeating Boyle. Boyle was indicted in 1973 for the three Yablonski murders; he was convicted in 1974 and received three life sentences. The union made important reforms. Early life, marriages and union career Joseph Yablonski, called "Jock", was born in Pittsburgh, Pennsylvania, on March 3, 1910, as the son of Polish immigrants, After attending public schools, Yablonski began working in the mines as a boy, joining his father in this industry. After his father was killed in a mine explosion, Yablonski became active in the United Mine Workers and began to advocate for better working conditions. He was first elected to union office in 1934. In 1940, Yablonski was elected as a representative to the international executive board. In 1958 he was appointed president of UMW District 5. As a young man, Yablonski married Ann Marie Huffman (November 5, 1913 – September 28, 2003). Their son Kenneth J. Yablonski was born in 1934. Yablonski married again, to Margaret Rita Wasicek (August 8, 1912 – December 31, 1969), an amateur playwright. They had two children, Joseph "Chip" (b. 1941) and Charlotte Yablonski, b. 1944. Both sons became labor attorneys, representing their father in his union activities and later in private practices. Charlotte became a social worker in Clarksville, Pennsylvania, where her family lived. She took leave to work in 1969 on her father's campaign for the UMWA presidency. Yablonski clashed