9/11 survivor met a stranger minutes before he died - 25 years later he finally found his sons

Firefighter Bill Spade who survived the North Tower collapse on 9/11 has delivered a fellow responder's final words to his family, 25 years on from the tragedy.

Spade and NYPD Emergency Service Unit officer John D’Allara met in the most catastrophic of circumstances.

They had known each other for just 25 minutes after meeting while helping people escape the North Tower, and, according to Spade, had ‘written their own obituaries’.

Speaking with the Sun following the release of National Geographic’s documentary 9/11: Reunited, the firefighter recalled: "Well, here we are in the middle of this tragedy - one tower coming down and the other minutes away from coming down - and in a matter of moments, we’re working together, and we’re talking about our families."

D’Allara, 47, told Spade about his wife, Carol, and their two sons, then aged seven and two. And in return, Spade shared details about his wife, Cynthia, and their two young boys, with the pair exchanging information their families would need in case only one of them made it home.

And heartbreakingly, only one did.

John D’Allara worked as an officer for 14 years prior to 9/11. (Legacy)

Twenty‑five years later, the firefighter has fulfilled a promise to the D’Allara family by delivering the NYPD officer's final words - 'I was thinking of you until the very end' - to his sons, who now work as a Marine reservist and a Bronx police officer.

Spade said: "He was thinking of his boys right to the very end.

“There were no lights on; it was completely pitch black. We were helping people out of the building and talking about his wife and two boys, and my wife and boys."

It was reported that D’Allara died less than a minute after the two escaped the building, and Spade later learned that the officer's last actions helped force open a jammed door, which saved roughly 20 civilians.

He recalled: "We left the North Tower about 30 seconds before it came down. John looked up and said, 'It’s clear. Everybody run'.

Spade finally delivered the officer's final words to his sons, 25 years on from 9/11. (National Geographic)

"At the time, I never thought the towers would come down."

As their rescue effort continued, the tower suddenly fell quiet, prompting those inside to realise it was time to get out.

D’Allara moved ahead of the others, checking the route was clear before they began making their way towards the exit.

But they had barely made it outside when the North Tower collapsed, with the first responder still inside the building.

Spade was caught in the falling debris and, knowing he had lost sight of John, curled up and prepared for the worst, fearing he would not survive either.

"As soon as the buildings came down and I realised they were no longer there, I went searching for a chief and said, 'We’ve got to go back and look for them'.

"Sure enough, months later, they were found there."