Two explosions went off around 3pm ET Monday near the Boston Marathon finish line. The Boston Marathon organizers have said they were bombs. Many runners and spectators were injured and taken to local area hospitals for treatment. Three people are confirmed dead and over 130 injured.
An FBI investigation is currently underway.
Celebrities took to Twitter to expect their shock and sadness over the day's events, including Joey McIntyre and Ethan Zohn -- who both ran. Bostonians Donnie Wahlberg and Ben Affleck weighed in, too.
This story is developing. More information to come.
Ethan Zohn @EthanZohn I'm OK. Most importantly, praying for those injured and affected by this. Still don't have a lot of info. Thanks for your love and concern
Joey McIntyre @joeymcintyre There was an explosion by the finish line about 5 minutes after I finished- I'm ok but I'm sure there are many hurt.
Ben Affleck @BenAffleck Such a senseless and tragic day. My family and I send our love to our beloved and resilient Boston.
Donnie Wahlberg @DonnieWahlberg No words to describe the pain in my heart, at this moment, in seeing my city torn apart this way. So sad. Please #pray4boston & the victims.
Donald J. Trump @realDonaldTrump My heart goes out to the people of Boston on this terrible day!
Donald J. Trump @realDonaldTrump We must change the laws of our land and seek fair but rapid trials for the perpetrators of terrorist acts (Boston) with harsh punishment!
Katharine McPhee @katharinemcphee Prayers for #Boston. I'm horrified.
George Takei @GeorgeTakei Keep on running on, Boston. #BostonMarathon
Derek Hough @derekhough My thoughts and prayers go out to the people of Boston
Colin Egglesfield @CEgglesfield My deepest thoughts and prayers go out to all those affected by the events today in Boston. We are with you in solidarity. #bostonmarathon
Billy Bush @billybush My 15 year old niece was at the finish taking photos. She walked away and one block later kaboom. 2 many Others not so lucky #Boston. Tragic
Harry Styles @Harry_Styles Just heard the news. So terribly sad. thoughts with everyone in Boston .x
Justin Timberlake @jtimberlake My thoughts and prayers are with everyone in the city of Boston and all of those affected by this terrible incident.
Katie Cassidy @MzKatieCassidy My heart goes out to those affected by #bostonmarathon
Sarah Hyland @Sarah_Hyland I'm so shocked to hear about the bombings at the #BostonMarathon #prayforboston
Kerry Washington @kerrywashington My heartfelt prayers go out to the city of Boston and everyone affected by today's incident. #PrayForBoston #bostonmarathon
Liam McIntyre @Liam_J_McIntyre Prayers and Love goes out those caught in this tragedy! BBC News - Boston Marathon rocked by twin explosions
Troian Bellisario @SleepintheGardn Just heard about #Boston from one of my favorite marathon runners. This is awful. Everyone send love and positive thoughts those affected
Busy Philipps @Busyphilipps25 4m Just heard about the Boston marathon tragedy. Trying to wrap my head around it. My thoughts and prayers are with everyone there.
Paloma Faith @Palomafaith 5m PFHQ: May everyone in Boston remain safe. All of our hearts to the victims of this terrible tragedy today. #prayforboston
Kunal Nayyar @kunalnayyar Boston. My heart is with you.
Kevin Williamson @kevwilliamson Dear Boston. Hugs.
Suze Orman @SuzeOrmanShow You never know what life holds.Boston is just another example of that. Take nothing for granted. My heart felt love goes out to Boston.
christina perri @christinaperri sending all my love and prayers to boston.
Chad Michael Murray @ChadMMurray Peace & prayers to all hurt in #Boston Stick together & love one another. Our thoughts are with u...
Cher Lloyd @CherLloyd My thoughts and prayers go out to everyone in Boston. Lost for words. Thinking of you all xxx
Joy Behar @JoyVBehar So sad to hear about the terrible tragedy in Boston. My thoughts go out to the victims and their families.
Nate Berkus @Nate_Berkus Praying for Boston
Jason Castro @jasoncastro So saddened by the tragedy in Boston.. what a broken world. #PrayforBoston
Dr Drew @drdrew I am so upset about The Boston Disaster. No it's more like the modern Boston Massacre.Throughts and prayers with my friends in Massachusetts
Kevin McHale @druidDUDE Watching the all the coverage of the horrific events in #Boston. Hurts my heart. No words--stay safe #thinkingofboston
Deena Nicole Cortese @DeenaNicoleMTV My heart goes out to anyone effected by what happened in Boston today .. So sad :(
Victoria Beckham @victoriabeckham Just seen the news, my thoughts are with the people of Boston x vb
Miley Ray Cyrus @MileyCyrus Sending peace & many blessings to Boston ❤❤❤
Donnie Wahlberg @DonnieWahlberg Just heard that @joeymcintyre is ok! Thanks to everyone for tweeting! Scared for everyone else in Boston. #PrayerForBoston please.
Danica Patrick The Boston marathon bombing makes you rethink ordinary events. Scary stuff.
Peter Facinelli Boston Marathon bombing? Why? Horrible. Just horrible.
Paula Abdul I was shocked to hear about the horrible explosions at the Boston Marathon. I'm holding the people of Boston in my heart.
Jenna Dewan-Tatum Oh man. Just heard the news about Boston. This is just awful. #prayforboston
Russell Simmons @UncleRUSH 1m prayers for Boston.
Dane Cook @DaneCook My prayers with everyone in Boston right now after this atrocious act of violence!!
Maria Menounos @mariamenounos Praying for everyone home in boston. Devatated at the news #bostonmarathon
Kim Kardashian @KimKardashian My heart is breaking for everyone effected or injured in the explosion at the Boston Marathon. God bless you all! My prayers are with you!
Ramona Singer @ramonasinger I hope everyone in Boston is okay!! My prayers and thoughts to those involved. Thank you to the first responders!
Lance Armstrong @lancearmstrong Just off the bike and getting the news from the Boston marathon. Thoughts & prayers go out to Dave M, his staff, all runners, and volunteers
andygrammer @andygrammer Boston- I love you. Praying for the victims at the marathon. My heart is with you.
Evan Longoria @Evan3Longoria Unfortunate events at the Boston Marathon, scary for all of us. Our thoughts are with the injured.
Scotty McCreery @ScottyMcCreery Prayers going out to everyone involved at the Boston Marathon.. #shocking
P!nk @Pink Our thoughts and prayers are with everyone affected by the explosions in Boston.
Nina Garcia @ninagarcia My thoughts are with the people from Boston
Rachel Federoff @RachelFederoff my heart goes out to all those affected by the horrible bombs in #Boston This is such a tragedy and disgrace.
Tom Bergeron @Tom_Bergeron Watching coverage of Boston Marathon explosions, heart in my throat.
Matthew Morrison @Matt_Morrison Thoughts are in Boston. #prayforboston
Wayne Brady @waynebrady God Bless any and everyone hurt Boston
Eva Longoria @EvaLongoria God be with the injured people! RT "@CNN: There has been at least one explosion near the Boston Marathon finish line…
Paramore @paramore All our prayers and love to everyone affected by the explosions in Boston today. Unbelievable :(
Backstreet Boys @backstreetboys We're sending our thoughts and prayers to everyone in Boston today #PrayForBoston
Chris Hardwick @nerdist 2 explosions @ Boston Marathon: https://nerdi.st/11iqM6G Authorities request texting only 2 keep phone lines open. If you pray, do it for them
Kate Gosselin @Kateplusmy8 My heart is heavy for all Boston runners, spectators, and all affected. Praying here.....
Chris Evans @ChrisEvans thoughts and prayers are with everybody in boston. heartbreaking...
Patton Oswalt @pattonoswalt "Look for the helpers. You'll always find people who are helping." -- Fred Rogers, on what to do when scary things are on the news #boston
Samantha Giancola @MTVsammi My thoughts and prayers go out to everyone in Boston, can't believe what I am hearing/seeing.
Pete Wentz @petewentz Boston be strong.
Mia Farrow @MiaFarrow Just located my daughter in Boston. Relieved she is fine but heartbroken for those who won't get this good news #prayforboston
Sean Hannity @seanhannity As we follow developments our hearts and prayers are with those in Boston
Arnold Schwarzenegger @Schwarzenegger My thoughts are with Boston. Thank you to the brave first responders who always run toward our greatest fears to save lives.
John Cena @johncena An evening of @WWE entertainment, overshadowed by an afternoon of horrible tragedy #PrayForBoston
SHAQ @SHAQ Thoughts & Prayers go out to the people of Boston... Very Sad News.
Michelle Williams @RealMichelleW Prayers up now! #BOSTON
Kylie Jenner @KylieJenner Sending prayers to Boston..
Peta Murgatroyd @PetaMurgatroyd Thinking of everyone in Boston. My heart is there #unfathomable #senselesscruelty
Beth Ostrosky @BethStern Thoughts and prayers to people in Boston right now
Alicia Keys @aliciakeys Shaken… My thoughts and prayers are with the city of Boston and those affected by this tragedy.
Zoe Saldana @zoesaldana My prayers and thoughts are with the victims who lost their lives today at the Boston marathon. Que Dios los tenga en su gloria. ZS
Aviva Drescher @AvivaDrescher My thoughts and prayers go out all in Boston.
Ellen DeGeneres @TheEllenShow Let's all send our thoughts, our prayers and our energy to the people injured in Boston. My heart is with you.
Roma Downey @RealRomaDowney “@northlandchurch: Prayers going up for everyone at the Boston Marathon.”Yes God Be with them all,we are praying here
Caroline Manzo @CarolineManzo Thinking of Our friends in Boston today stay safe our hearts go out 2 victims & families
Kevin Jonas @kevinjonas prayers go out to everyone in Boston. We all love you and we are praying for you
Brandi Glanville @BrandiGlanville Thoughts going out to the people hurt in the Boston marathon victims :(
Wendy Williams @WendyWilliams My thoughts and prayers are with all those people affected by the tragedy in Boston today at the marathon. #prayforboston
Lea Michele @msleamichele Sending my thoughts and prayers to everyone in Boston right now....
Larry King @kingsthings My thoughts are with those injured in Boston. Details are sill coming in, but we need to not jump to conclusions without all the facts
DJ Pauly D @DJPaulyD Heart And Prayers Go Out To Boston ...
COMMON @common Prayers up for the people in Boston!
Pandora Vanderpump @PandoraVT I hope all of you in Boston are ok! Sending my thoughts and prayers to anyone affected. x
Danica Patrick @DanicaPatrick The Boston marathon bombing makes you rethink ordinary events. Scary stuff.
Kelly Osbourne @MissKellyO Praying for #Boston
Mia Hamm @MiaHamm Boston, we are praying for you.
Josh Duhamel @joshduhamel Thoughts & prayers go out to Boston. #prayforboston
Peter Facinelli @peterfacinelli Boston Marathon bombing? Why? Horrible. Just horrible.
Mitt Romney @MittRomney Our hearts are heavy with the news out of Boston today. #PrayforBoston
America Ferrera @AmericaFerrera Sending love and good thoughts to everyone in Boston. My heart is heavy for the victims and their families, and for the Boston community.
Omar Epps @omarepps Prayers up for the people effected in Boston!
CeCe Frey @CeCeMissXtotheO Oh my God... Please save Boston this is just insane....
Ed Sheeran @edsheeran #prayforboston
Paul Ryan @PRyan My thoughts and prayers are with the people in Boston. #PrayforBoston