NBA Cancels Celtics Game After 2013 Boston Marathon Bombings; Boston Celtics' Rajon Rondo, Kobe Bryant, LeBron James, NBA React on Twitter

The tragic bombings on Monday that occurred in Boston sent shock waves through the sports world, prompting the NBA to cancel Tuesday's Boston Celtics game against Indiana.

After the twin bombings that occurred on Monday afternoon in Boston, Mass., during the 117th annual Boston Marathon, the NBA issued a statement announcing that the game was cancelled, reported Sports Illustrated.com.  The game will not be rescheduled.

"The NBA expresses its sympathy to all those affected by the tragedy in Boston earlier today," an NBA spokesperson said in a statement on Monday.

With the Celtics set to meet the New York Knicks in the first round of the NBA playoffs, it has yet to be determined if the bombings will have any impact on the series, which begins on Saturday at Madison Square Garden in New York.

The sports world was buzzing with tweets and messages on social media from athletes around the world as news trickled in of the bombings 

So far, two people are reported dead while dozens of bystanders have been injured after two bombs exploded at the finish line of the 26.2-mile marathon that was attended by thousands in Boston. President Obama, in a press conference on Monday, said that authorities were still investigating and vowed that those responsible would "will feel the full weight of justice."

Around the NBA, several players were grieving or sending their prayers to the victims of the bombings on Twitter.

Boston Celtics star point guard Rajon Rondo, currently mending thanks to season-ending ACL surgery, tweeted "Sending prayers out for Boston," followed by the hashtag "#PrayForBoston."

Celtics player Jared Sullinger tweeted, "Just leaving the gym and hearing about the explosion hope everybodys okay........."

"Damn!! What's going on in Boston?? Hope ppl are safe," tweeted Celtics guard Courtney Lee.

"The Celtics family sends its thoughts and prayers to the friends and families affected by today's tragedy in Boston. Stay safe," the message on the Celtics' official Twitter page read.

Kobe Bryant, who sustained a season-ending Achilles injury on Friday, posted a link to his new Instagram page with a message of support for the victims of the Boston bombings that read "Hearts are with Boston."

"#unity #peace #love #prayer," Bryant tweeted along with the link.

Miami Heat superstar LeBron James tweeted, "Prayers goes out to those involved/hurt in #BostonMarathon. WTF is wrong with people man. Just sad."

Golden State Warriors star Stephen Curry posted, "What's wrong with people man! An innocent event can't go without incident. Prayers for all in Boston and their families."

Los Angeles Lakers star Pau Gasol tweeted in English and Spanish, "Shocked and sad to hear about the explosions at the Boston Marathon today. There are things that I will never understand. #PrayForBoston"

Brooklyn Nets star Deron Williams tweeted, "#rp take some time to say a prayer for the people affected by the events today in Boston. this world..."

"Saddened by the news of the explosions at the@bostonmarathon. Praying for everyone impacted by this tragedy.," tweeted the Celtics' Chris Wilcox.

"I pray for all the people that was there in Boston," tweeted Indiana Pacers forward Lancer Stephenson.

"From movie theatre shootings to Marathon explosions, Is anywhere safe? This works is crazy. Prayers go out to ill that have been affected," tweeted the Phoenix Suns' Jared Dudley.

Washington Wizards star guard John Wall posted, "#PrayForBoston."

Wizards guard Bradley Beal tweeted, "Thoughts and prayers go out to those affected in Boston !"

"My thoughts and prayers to all of Boston," tweeted Chandler Parsons of the Houston Rockets.