The bombings were documented almost into the instantly by horrified spectators never imagining that they would become modern day reporters. It was reality of the gruesome attacks -- and millions... See More
The bombings were documented almost into the instantly by horrified spectators never imagining that they would become modern day reporters. It was reality of the gruesome attacks -- and millions responding on Twitter FaceBook and instead Graham. From celebrities to young school children. The bombings in Boston are unique not just for their stunning intrusion into an American tradition. But because in another -- they became the first US terrorist attacks of the social media generation. My friend finished. -- me. The explosion happened right before they finish they're all -- I learned from 8 o'clock the power social media. Some of the earliest reports that something had happened Monday afternoon came directly from tweets along the race course in the immediate aftermath of the first explosion. The news spread -- social media people start to see that something's going on. And then that second step is really sort of the bigger picture within moments still images text. Even short video clips began rocketing across tablets and mobile phones. Making their way into news coverage very very loud hit the ground -- At times the images captured in distributed in real time without filters were shocking and brutal. Leading some online to express their discomfort. Hearing about explosions are bad enough but the -- showing blood on the sidewalk one Twitter user wrote. That's horrific. -- -- of a Boston street covered in blood no words tweeted another. -- that was different here is we had these images and they were really graphic on FaceBook in particular mean. You really couldn't close out of those images. But just as the events unfolded on social media so too did immediate grassroots response -- those living nearby offering an online document to house runners evacuated from their hotels. To Google which launched a person finder service to help reunite lost friends and family members still despite all the technology involved. Perhaps the greatest power of social media Monday was the ability to remind everyone of what. Really matters. And two of Boston's most famous natives Ben Affleck and Mark Wahlberg took to social media sites to express their condolences. The Catholic posting on FaceBook quotes such a senseless and tragic day in my family and I send our love to my beloved resilient Boston. -- tweeting thoughts and prayers with my hometown Boston today of course he was just here with you yesterday on the show -- -- -- and who would have thought that the -- would have turned the way it did so tragic and and yet the power of social media certainly brought us all together and kept us connected to thank you -- -- and we appreciate it.
This transcript has been automatically generated and may not be 100% accurate.