Mr Thomas O'Brien was born in Bunavie, Pallas, Grean, Co Limerick, Ireland on 1 March 1886.1
He was the son of Patrick O'Brien (b. circa 1835), a farmer, and Margaret Tobin (b. circa 1854), Limerick natives who had married on 19 February 1873 in Grean, Co Tipperary.
He was brother to eight known siblings: Mary (b. 27 December 1873), Patrick (b. 19 May 1875), Winifred (b. 1 June 1877), Bridget (b. 23 April 1879), Patrick (b. 22 May 1880), Margaret (b. 5 May 1883), Ann (b. 20 November 1888) and Bryan "Barney" (b. 26 June 1891).
His father died on Christmas Day 1893 following an attack of acute bronchitis, and the remaining family appear on the 1901 census living at house 4 in Bunavie, Grean. Thomas was described as a farmer's son with his mother and his brother Pat by then operating the farm. His mother died a few years later from liver disease on 12 August 1905 aged 50. By the time of the 1911 census only Thomas' brothers Pat and Barney are listed at the family home, 7 Bunavie, but his own whereabouts are not clear.
Thomas later became involved with another Limerick native, Hanora "Hannah" Godfrey (b. 1882), a native of Cappamore. It is not clear if the two were ever officially married (there is no known record that they ever were, in Ireland at least) but by early 1912 it was clear that Hannah had fallen pregnant and it was decided that the couple should emigrate.
Thomas and Hannah boarded the Titanic at Queenstown as third class passengers (ticket number 370365 which cost £15, 10s) and he was described as an agricultural labourer. They were travelling to Chicago, Illinois where Thomas' sister Mary Hunt lived at 638 Sherman Plaza. It is believed that he had several other siblings living in the Chicago locale.
Thomas died in the sinking and his body, if recovered, was never identified.
His widow Hannah later gave birth to their daughter on 3 September 1912 and named her Marion Columba O'Brien.
In the wake of Thomas' death came a wrangling over compensation between his widow and his family back in Ireland. Hannah was soon able to produce evidence that she and Thomas were married and she went on to benefit from various relief funds. In a terse letter to her sister-in-law Mary Hunt, Hannah said:
"You needn't worry about me. My baby and myself will be alright. I knew ye were all trying to get some money. I produced my marriage certificate, and I had the nearest claim. So you nor the lawyer needn't bother..."
Hannah was remarried and had a son before her untimely death in 1918.
His daughter Marion, a Titanic survivor in her own right, later married an Irishman, William J. Hanlon (1905-1975) and had one son and two daughters.
She lived in Albany up until widowhood when she transferred to Tennessee where her daughter Catherine lived. She died in Manchester, Tennessee on 4 July 1994 aged 81 and is buried in St Agnes' Cemetery, Menands, Albany.