Moments of silence hit leadoff on Opening Day throughout Major League Baseball on Monday.

The celebration of a season couldn't begin across the country without remembering one our nation's saddest tragedies: December's Sandy Hook school shooting, which shook victims, their families, friends, the community of Newtown, Conn., and the entire country.

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In the Bronx, the Yankees and Red Sox dedicated their Opening Day contest to the victims of the Sandy Hook shooting, and all of MLB's players, managers, coaches, umpires and on-field personnel wore a ribbon patch on their uniforms to honor those who lost their lives or their loved ones on Dec. 14, 2012.

"I think it's important to say thank you," Yankees manager Joe Girardi said Monday. "The town of Newtown went through so much during the last four or five months, and you think about being a responder. Sometimes we don't think about what they go through and how important they are during a situation like that."

"Just honoring them, being there for them, is outstanding," added Yankees closer Mariano Rivera. "We cannot change what happened. I wish we could. But at the same time, we're trying to bring them a lot of good moments and just trying to take the tragedy away from their minds for a little bit."

In Pittsburgh, managers Clint Hurdle of the Pirates and Dale Sveum of the Cubs, players of both teams, umpires and all on-field personnel wore a symbolic ribbon patch on their sleeves in honor of the Newtown, Conn., victims. So, too, did the Reds and Angels in Cincinnati.

Twins Hall of Famer Rod Carew, who joined the Marine Corps in 1965 and served active duty as a combat engineer before serving as a reservist from 1966-71, raised the U.S. flag on Target Plaza in right field after a video and moment of silence for the Newtown victims in Minnesota. Nathan Perttula, 11, and Cole Harms, 12, of Crystal Little League raised the Hennepin County flag, while the Twins Territory flag was raised by Minneapolis Mayor R.T. Rybak.

The Mets recognized those affected by another difficult moment for the tri-state area, bringing more than 500 first responders of Hurricane Sandy on the field for the national anthem. The Mets also handed out more than 1,000 tickets to citizens involved in the storm response, and honored first responders from all branches.

"It means the world to us," said Lt. Peter O'Neill of the NYPD. "How many times do you get to stand on the baseball field for a National League team? We stand in front of everyone and everyone says 'Thank You' to us. It doesn't happen very often. We appreciate it. I brought my son, and he's having a good time."

The games, and the usual -- and, at times, unusual -- mix of Opening Day pomp and pageantry also were on display throughout MLB on Monday.

In the nation's capital, fans celebrated the Nationals' breakthrough 2012 season, as the club unveiled its NL East championship banner atop the right-field scoreboard, and passed out awards before a standing-room-only crowd at Nationals Park. General manager Mike Rizzo accepted his MLB Executive of the Year Award, Davey Johnson received his NL Manager of the Year Award and first baseman Adam LaRoche was presented with NL Gold Glove and Silver Slugger awards.

In Pittsburgh, the Pirates recognized United States Marine Corp Cpl. Brandon Rumbaugh, a double amputee who lost both legs during his second tour of duty in Afghanistan, during violinist Noah Bendix-Balgley's rendition of the national anthem. Pirates chairman Bob Nutting hopes to host and recognize more members of the Wounded Warriors as the season goes on.

In keeping with a year that's seen them add a ton of big-name talent, the Dodgers put plenty of star power on the field before their season opener. Magic Johnson looked ready to throw out the first pitch before manager Don Mattingly walked out to the mound and signaled for Hall of Famer Sandy Koufax, who then tossed the ball to 1988 NL Cy Young Award winner and World Series MVP Orel Hershiser.

Meanwhile, in Cincinnati, the day was all about time-honored traditions. The city's 137th Opening Day game began with the 94th edition of the Findlay Market Parade through downtown. Reds great George Foster served as grand marshal, while Bronson Arroyo and Mat Latos rode in a convertible through the crowds. Inside Great American Ball Park, hosting its 11th Opening Day, Joe Torre threw the first pitch to Brandon Phillips, Torre's second baseman on the U.S. World Baseball Classic team.

"It's a holiday here," Reds right fielder Jay Bruce said. "It's something that is very, very special to the fans and to myself. It's something I look forward to every year.

"Regardless of who you're playing, it's still baseball and it's still Opening Day in Cincinnati."