[Updated from 3.49 pm to 4.23 pm]
LIVE VIDEO: Explosion at Boston Marathon nbcnews.to/15b1V9b
— NBC News Videos (@NBCNewsVideo) April 15, 2013
BREAKING NEWS: 2 dead, 22 injured in Boston Marathon explosions.
— Boston.com News (@BostonDotCom) April 15, 2013
Video of the first explosion, lots of screams. Runners stopped in their tracks. youtube.com/watch?feature=…
— Andrew Kaczynski (@BuzzFeedAndrew) April 15, 2013
CBS reports “people have seen dead bodies” at the blast site, some children wounded and people unconscious and with amputations. #boston
— NYC ARECS (@nycarecs) April 15, 2013
I saw people’s legs blown off. Horrific. Two explosions. Runners were coming in and saw unspeakable horror. — Jackie Bruno (@JackieBrunoNECN) April 15, 2013
I was in office right above it. There was a primary and a secondary explosion. I ran outside to help. Blood on sidewalks & 10-12 casualties.
— Bruce Mendelsohn (@brm90) April 15, 2013
Video: @bostonglobe video of moments after explosion – youtu.be/gOzoq1rxyOw [graphic]
— Dave Wyllie (@journodave) April 15, 2013
Police say are they still finding “secondary devices,” pleading with crowd to go home
— Jim O’Sullivan (@JOSreports) April 15, 2013
! RT @sarah_boxer: NBC: Law enforcement officials who spoke to @nbcnews believe the explosion was at least 1 small IED – a homemade bomb
— Andrew Kaczynski (@BuzzFeedAndrew) April 15, 2013
RAW video of second explosion: youtu.be/7jMYObtjToU #bostonmarathon @wbur
— Dæn Russell (@deanwrussell) April 15, 2013
BREAKING NEWS: Police will have controlled explosion on 600 block on Boylston Street
— Boston.com News (@BostonDotCom) April 15, 2013
New York Times map of Boston explosionstwitter.com/digg/status/32…
— Martin Gelin (@M_Gelin) April 15, 2013
Boston EMS/police/fire saying they need ppl on social media to let ppl stuck in bars & restaurants to know a street sweep is happening
— attackerman (@attackerman) April 15, 2013
If you know someone in Boston: don’t call their cell; leave open for emergencies. Send text messages. If you know they’re ok, connect later.
— Seth Mnookin (@sethmnookin) April 15, 2013
Biden Responds To Boston Explosion While On Gun Conference Call livewire.talkingpointsmemo.com/entry/biden-re… via @pemalevy
— Josh Marshall (@joshtpm) April 15, 2013
Assuming it’s real, I have a feeling this is going to be the iconic image. Boston’s finest twitter.com/BGlobeSports/s…
— Sam Graham-Felsen (@samgf) April 15, 2013
RT @stevebruskcnn John King told by state and local officials there was no known credible threat prior to the explosions.
— Andrew Kaczynski (@BuzzFeedAndrew) April 15, 2013
TV networks: could you wait before rolling out terrorism experts for worst-case speculation? Bloomberg TV, looking at you
— James Fallows (@JamesFallows) April 15, 2013
Fox just said “terrorist attack” too.
— Zack Beauchamp (@zackbeauchamp) April 15, 2013
The Globe’s websites are down. But those looking for a reliable source for information can follow this live blog: bo.st/XCLv4T
— Matt Viser (@mviser) April 15, 2013
Mackey is also live-blogging, as is The Guardian. Short clip of the explosion here. Top photo by Bruce Mendelsohn. Deadspin is compiling many more.
The Dish 