Breaking News: Explosions At Boston Marathon - Ground Footage (Boston On Lockdown) (VIDEO)

It happened around 2:45 p.m. outside Marathon Sports on Boylston Street, according to WBZ-TV's Lisa Hughes, who was near the scene covering the marathon.

There were two "incredibly powerful explosions just seconds apart," assumed to be bombs.

Some people were reportedly missing limbs. Others had blood on their heads.

"There's a lot of blood" at the scene, according to WBZ-TV producer Ken Tucci, who reported seeing more than ten people taken away from the scene on stretchers.
Please send your prayers and love to the victims...

[Update, 4:58 p.m. ET] New details from Boston Police Commissioner Ed Davis:

-- A third explosion happened at the John F. Kennedy Presidential Library "about a half-hour ago." The library is about 5 miles southeast of the Boston Marathon finish line.
-- Police don't immediately know whether that explosion is related to the two near the Boston Marathon finish line.
-- The two blasts near the finish line — along Boylston Street near Copley Square — "happened 50 to 100 yards apart."
-- "We're recommending to people that they stay home ... and that they don'r go anyplace and congregate in large crowds."

-- Relatives of people who may be missing in the area can call the mayor's hotline at 617-635-4500.

-- Anyone who has information about the bombings or saw anything suspicious can call 1-800-494-TIPS.