Michael Horrigan was born in 1865 in Liverpool, Lancashire, the son of Moses and Catherine Horrigan. He was married to Mary Ann Horrigan (née Gillard) and they lived at 25, Aspinall Street, Kirkdale, Liverpool.
He served as a greaser in the Engineering Department on board the Lusitania and was killed when she was sunk.
His body was not recovered and identified afterwards, and consequently, he is commemorated on the Mercantile Marine War Memorial at Tower Hill, London.
He is also commemorated on a memorial plaque in St. Alphonsus Roman Catholic Church, Great Mersey Street, Kirkdale, Liverpool, not far from where he lived.
In keeping with all crew members, Cunard paid Michael Horrigan up until 8th May, 24 hours after the sinking and eventually, the balance of wages owing to him was forwarded to his widow Mary Ann. The Liverpool and London War Risks Insurance Association Limited also granted a yearly pension to Mary Ann Horrigan to compensate her for the loss of her husband which amounted to £19-1s-3d. (£19.06p.) which was payable at the rate of £1-11s-10d. (£1.59p.) per month.
Register of Births, Marriages and Deaths, 1901 Census of England and Wales, 1911 Census of England and Wales, Commonwealth War Graves Commission, Cunard Records, George Donnison, UniLiv. PR 13/24, PRO BT 334.