Family uncovers a Titanic story
Mr McQuillan did drown in the disaster, but his body was found and brought ashore at Halifax in Nova Scotia.
Ninety-three years ago, back in the ship's home city of Belfast, his grieving family could only believe what they saw in the papers.
The Belfast Telegraph of 4 May 1912 revealed Mr McQuillan was not one of the survivors and that the bodies of the missing Belfast firemen who stoked the Titanic's engines "lay in a sailor's grave, two miles beneath the ocean".
In a cruel twist of fate, just two days later, William McQuillan's body was buried in grave 183 in Fairview Cemetery, Halifax, Canada.
Until last week, his family assumed he was just one of about 1,000 people lost at sea in the disaster.