In the 6,210 days since that fateful morning, not one has passed where Bruce Boudreau hasn't thought about what might have been.
It was early September in 2001 when Boudreau, then the head coach of the Los Angeles Kings AHL affiliate in Manchester, New Hampshire, hopped in a car and drove with one of his best friends, Ace Bailey, to Lake Placid, New York.
The two were among a host of Kings personnel headed upstate to celebrate the wedding of the daughter of Bill Flaherty, at the time, the Kings' Director of Personnel.
While at the wedding, Andy Murray -- then the Kings head coach -- told Boudreau and his staff to change their flights scheduled for the following Tuesday. Instead, Murray wanted them in Los Angeles on Monday for a coaches dinner.
"I was the American League coach at the time," Boudreau said. "So I was going to do whatever Andy Murray wanted me to."
Boudreau contacted John Wolf, the Kings travel coordinator, and had his flight changed from Tuesday to Monday. Along with Murray and his staff, Boudreau dined, shared stories and had one final evening of relaxation before the grind of another training camp and NHL season would begin.
The next morning, the world changed forever.
On their way home from the wedding, Boudreau worked his hardest to get Bailey to change his ticket too.
Bailey, the Kings' Director of Pro Scouting, was one of the most popular figures in the organization. A beloved former player, Bailey was once tasked with being Wayne Gretzky's on-ice protector as a member of the Edmonton Oilers.
That was just his personality, and guys loved him for it.
Boudreau said the cost to move his ticket up one day was about $750 -- too much, according to Bailey. It was an amount, he said, that wasn't in the budget.
As the two reached Manchester on Sunday night, Boudreau exited his buddy's car, grabbed his bag and began walking towards his house.
"I lived in a cul-de-sac, and this image has always stayed with me. I was waving goodbye to him," Boudreau said. "And he said, I'll see you Tuesday morning."
That morning, September 11, 2001, Bailey and Kings scout Mark Bavis arrived at Logan International Airport in Boston ready to fly to Los Angeles aboard United Airlines Flight 175. It was a flight Boudreau was supposed to be on with them.
Scheduled to leave Boston at 8 a.m. ET, it took off at 8:14.
Just 51 minutes into its journey, United 175 crashed into the South Tower of the World Trade Center in New York City.
A little before 6 a.m. Pacific time, Boudreau's phone buzzed. His wife, Crystal, implored him to turn on the television. American Airlines Flight 11 had just flown into the North Tower of the World Trade Center.
At the time, nobody was certain what was happening. Was it an accident? Was the plane suffering from mechanical issues?
Few could have envisioned the horror that was transpiring in the skies over the eastern part of the United States. Around the same time Flight 11 crashed in New York, United 175 carrying Bailey and Mavis was hijacked somewhere over northwest New Jersey.
After the first plane went into the building, Boudreau ran down the hall at his hotel and knocked on the door of his assistant coach in Manchester, Bob Jay, himself a Boston native.
The two watched together in horror as Flight 175 smashed into the second tower.
"That was us, right there," Boudreau said. "We were on that flight."
Boudreau didn't know at that moment that his best friend was gone, or that the flight he was supposed to be on had been hijacked and crashed into the World Trade Center, but it wouldn't take long to find out.
Within minutes, the flight information had been broadcast to a national audience.
"Once they identified it as coming from Boston to L.A., Crystal started getting a bunch of phone calls," Boudreau said.
Perhaps the hardest part of one of the hardest days of his life came next.
The request to change his flight came so quickly, Boudreau had forgotten to inform his children that he had traveled on Monday. His teenaged kids, in Canada with their mom, watched the events on TV and ran home from school in tears, believing their father had been killed.
It's a memory that Boudreau still struggles to talk about.
"Sometimes when you're away from your kids, you feel bad because you're not there. You don't realize how much they really love you," Boudreau said. "When I finally got a chance to talk to them later that day, you could tell in their voice that they were so happy I was still on the other end of the line."
Once Boudreau realized that it was indeed his flight that went into the World Trade Center, the shock and sadness became overwhelming.
"I was pretty much numb," Boudreau said. "Ace and I flew together everywhere all the time. But then you just realize it ... that was supposed to be me. That was supposed to be me, there's no ifs, ands or buts about it. I was taking that plane if Andy Murray hadn't called me and had we not gotten permission for it."
Until he found out for sure, there was still hope that Bailey and Bavis were not on the plane. Perhaps they missed the flight, or something had come up that forced them to stay back.
But by mid-afternoon, it was clear that wasn't the case. Everyone knew how close Boudreau and Bailey were, so Dave Taylor, the Kings General Manager at the time, asked him to leave the room where staff had gathered to watch events unfold.
In the parking lot, Taylor informed him that his friend had died in the attacks.
Boudreau lost it.
"There's not much you can do," Boudreau said. "I was numb. It made for an incredible training camp ... I was just going through the motions. I'll never forget, we all had to fly home a few days later ... it changed the world."
Boudreau is well known as a movie buff, so when all of the films and documentaries began coming out about the day in the years that followed, it was a bit surreal.
"You just remember how close you are to not being around," Boudreau said. "It happens every day. People live or die. But I guess it wasn't my time. I got very lucky."