Sean Aloysius O'Brien was a male Human coal mine worker on Earth in the late 19th century and 1900s. He was an ancestor of Miles O'Brien. He was born in the 19th century and was a union leader in Pennsylvania in 1902. Sean and a group of employees went out on strike against the owners of a coal mine and refused to open the mine until their demands were met. He made the ultimate sacrifice for his union: he was found dead in the Allegheny River with 32 or 34 gunshot wounds in his body a week before the strike ended.