Those people were well represented on Monday night. The first pitch was thrown out by Bill Spade, the only surviving member of Rescue Company 5 in Staten Island.
The national anthem was sung by Army Specialist Vicki Golding, and the crowd at Camden Yards helped honor the memories of the 9/11 victims with a lengthy moment of silence before the game. After that, it was time for baseball, but many of the Orioles said they remember exactly where they were in 2001.
"I was in a hotel in St. Petersburg Beach," said Baltimore utilityman Chris Gomez. "I was playing with the Devil Rays, and for some reason I was up that early. You turn on the TV and it was on, and you think you're still sleeping when you see what's going on. I was like everyone else -- just glued to the TV the whole time."
"I can remember just sitting in the house the entire day, just watching television in shock," said Roberts, who was living with teammate David Segui at the time. "I think our games were canceled for four or five days, and I don't think I left the house for more than two hours. It was one of those things that was so surreal.
"At first, you didnt know what was going on or why it was happening. You hadn't heard the whole terror thing yet. Once you realized what had happened, it was mind-blowing."
Baseball hasn't changed much since that fateful day -- unless you count the world around it. Kevin Millar, Baltimore's first baseman, said so much has changed in regard to travel and the atmosphere around everyday life.
"It's a very small thing that we do on this baseball field. It's fun, but things like 9/11 show you how small it is," he said. "The name Osama bin Laden still resonates, and every time you travel you have to go through the sama balogna. It's a wakeup call for everybody on a daily basis. Now, you see soldiers with guns more often.
"You just can't forget that stuff. It's real life. It's real families that don't have their moms or dads. You can't run away from it. But it makes you listen to those songs and understand that we have to be one [nation]. What New York did that year, coming together that way, was amazing."
New York's Yankee Stadium still plays God Bless America at every home game, a tradition that started after 9/11. Several other stadiums have their own policies, and Camden Yards only plays the patriotic song on Sundays. But every time it's on, it means something -- to the fans in the stands and the players on the field.
"You still know why they're singing it," said Millar. "You have an appreciation for the flag, our freedom and our safety. That day, I think everyone felt the same. You felt invaded, and that's not supposed to happen to the United States of America. Now, we're battling terror to this day, and it's going to go on for a long time."
"We had probably gotten away from remembering our country -- all the freedoms we have and what an incredible place it is to live in," added Roberts. "I think it's a great way to remember that. In the heat of playing, when you feel like baseball's the most important thing in the world, that song comes on and makes you think.
"It's no different if you have flags on the field or someone important singing -- it always has the same meaning."