"My dad's a plumber and I went down to the scene two days after the buildings had collapsed. I was 17.
"To be there and to see the heroic men and women looking for survivors, doing their best to find anyone - it's one of those things that is burned into your memory for the rest of your life.
"One of my best friends lost his father that day. He was a rescue firefighter."
Petri said he would keep those who died in his thoughts and in his heart as he went into the game. His friend had advised him that there were "a lot of souls up there cheering for us, supporting us".
It would be tough to go from an emotional church service to an opening game for the tournament, but Petri said it would do the team good to play for their country.
"It will definitely be a difficult transition and a challenge to take that emotion and funnel it into a good performance. It can only be a positive thing for us: the opportunity for us to represent the country on such a big day with the idea of so many people back home watching it on television."
Francis said the ceremony needed to honour the people from 70 countries who died that day.
Members of the congregation will sing both national anthems as well as the hymn Amazing Grace. The ambassador will speak, a minute's silence will be observed, and the church bell will toll 10 times.
"The service for me is for all the people of New Plymouth and those Americans who find themselves at our home at a defining time in their nation's history," said Francis.
From the time the service ends to kick-off, the team will get their game faces on. "The guys will have absolutely no problems when the whistle blows to switch gears and start playing rugby," said Petri.
