Published Wednesday, 11 April 2012
One hundred years to day later, commemorations are being held and Irish President Michael D Higgins has led tributes to the victims of the tragedy.
"This great liner, renowned as a triumph of engineering even before entering into service, departed exactly 100 years ago today over a grey horizon to meet with disaster and to attain a unique position in maritime history," he said.
"What is it about this story that reaches us today across the generations?
"It is a story of genius and industry, achievement and pride, romance and tragedy, hope and despair, courage and cowardice, responsibility and negligence, loss and redemption.
"It is the stuff of myth and legend but it also actually happened."
Irrespective of their social distinctions as passengers, the only classification on the Titanic that ultimately mattered was whether one was a victim or survivor.
President Michael D Higgins
On 11 April 1912, Dr John Simpson made the journey to Southampton to take up his post as assistant surgeon onboard Titanic and made time to pen a letter to his mother Elizabeth.
"Dear mother," he wrote, on Titanic-headed notepaper.
"I travelled from Liverpool on Monday by the 12 o'clock train and arrived on Ward at 10pm feeling pretty tired.
"I am very well and am gradually getting settled in my new cabin which is larger than my last. This seems all the time as if it was the Olympic and I like it very much.
"I am a member of the club now which is an advantage. Be sure to let me know how father gets on with his club.
"I was glad to get away from Liverpool as usual and don't intend to go up for a month or two. I found my two trunks unlocked and 5 or 6 dollars stolen out of my pocket-book. I hope none of my stamps have been stolen.
"Did I have my old portmanteau when I borrowed the kit bag? I think not."
He signed off: "With fondest love, John."
When the ship arrived at Cobh, the letter was among those taken ashore to be forwarded to their destinations - but while it arrived safely with the family, Dr Simpson was to suffer the fate of over 1,500 people on board.
The 37-year-old went down with the Titanic.
Handed down through generations before it went missing, his letter is now to be returned to Belfast after a mystery benefactor stepped in just last month.
It had been due to be auctioned in New York with a reserve price-tag of $34,000, but was instead "bought on behalf of Belfast" for an undisclosed sum.
"It will be coming back to Belfast and will be shown in a public display in Belfast, after all these years," Dr Simpson's great-nephew John Martin told UTV.
"We are so thankful to the benefactor."
© UTV News