Navy SEAL who killed Osama bin Laden wrote emotional note to family thinking he would die on mission

The former Navy SEAL who claims to have fired the fatal shot which killed Osama bin Laden has revealed how he prepared for the do or die mission.

There were no guarantees that Rob O'Neill would ever return when he left his family home in 2011 for the historic operation to take down the al-Qaeda leader.

He explained that he had made peace with the fact him and his fellow US Navy SEAL Team 6 members could be killed, or thrown in a Pakistani prison - which he reckoned would be a 'miserable way to go'.

Obviously, this wasn't the outcome of the covert and ridiculously risky mission that was known as Operation Neptune Spear, and O'Neill did reunite with his loved ones.

But before he left to hunt down bin Laden and his fate was still hanging in the balance, the dad penned a series of emotional letters to his family, just in case he didn't make it back home.

O'Neill, 48, has gained a lot of notoriety since all of this went down 14 years ago, as he publicly claimed that he was the SEAL who fired the kill shot.

Rob O'Neill, 48, admitted 'tears were hitting the page' as he penned the letters to his loved ones (YouTube/High Performance)

He claims to have blasted bin Laden 'in the face three times' after the terrorist was tracked down to a compound in Abbottabad, Pakistan, in May 2011.

'High stakes' doesn't really cut it when it comes to describing this situation, and O'Neill admitted that he considered it a 'very high probability' that it could have been the last mission he might ever go on.

During a recent appearance on Jake Humphrey and Damian Hughes' High Performance podcast, the ex-SEAL explained what it was like saying goodbye to his loved ones, not knowing if he would ever see them again.

O'Neill explained that he feared his team could be 'shot down on the way in' or out, or that bin Laden might 'blow himself up and kill everyone in the house' when US forces entered.

"Getting shot at is really easy, getting blown up - I'm assuming - is really easy," he said. "But looking your kids in the eyes and you're aware that this could be it, this might be the last time we ever see each other...

"There's a huge difference between kissing your kid good night, and kissing your kid goodbye."

The dad claims he was the one who fatally shot Osama bin Laden during the 2011 mission (Getty Images)

O'Neill said he had done this emotional goodbye '11 different times' with his daughters, but it didn't make it any easier, especially as he couldn't even explain where he was headed.

"We weren't allowed to tell anyone where we were going," the father said. "We just finished a deployment to Afghanistan, we were supposed to be training around the country, around the world, different things - but not going to war.

"Which is part of the reason they picked us (SEAL Team 6), because it wouldn't be a red flag. Leaving the house was tough.

"My youngest daughter, I think she might have been three at the time, I had to leave and that was hard. I couldn't tell her where I was going and I said, 'But I'll be back soon'.

"So she went upstairs and she grabbed a little teeny pink Hello Kitty carry-on. I think she probably put a pillow in it.

"She put it in front of the front door and said, 'Well, I'm leaving this here dad, and when you come home, you get to take me on vacation'.

"And that's tough, because you have to leave, you can't tell anyone - including my wife - where I'm going."

After his youngest's sweet action tugged on his heartstrings, O'Neill recalled how he sit down to handwrite individual notes to each of his daughters after he arrived in Afghanistan ahead of the mission.

The dad said he penned these letters to the future versions of his children, explaining: "My middle daughter was seven and I didn't write the seven-year-old a letter, I wrote a letter to the 27-year-old woman.

"'I'm really sorry I missed your wedding, I know you were beautiful. And thanks for taking care of your mom and your sisters, but you know what we did was noble'. Kind of explaining - tears hitting the page - to each one of my daughters and then to my family. Then, the hard part after that was that I had to put it in a manila envelope and I couldn't give it to a friend, because if I die all my friends are going to die with me."

O'Neill said an hour before the mission, he had to find someone who wouldn't be on one of the choppers bound for Pakistan to give the letters to for safekeeping.

"I said, 'Hey, when you see me tomorrow, I want this back - if you don't see me tomorrow there are instructions inside the envelope, do what it says'," O'Neill added.

"And he goes 'How will I know?' And all I could say was, 'Trust me, you'll know'."

Thankfully, these letters didn't ever need to be sent, as Operation Neptune Spear was a success.