What we know about the Boston bombing and its aftermath

Updated 5:54 AM EDT, Thu April 18, 2013
(CNN) —  

After explosives killed three people and wounded about 180 others during the Boston Marathon, details continue to trickle in as investigators sort through evidence.

WHAT’S NEW

– Obama declared an emergency in Massachusetts and ordered federal aid to supplement state and local response efforts.

PREVIOUSLY REPORTED

Details on the bombs

– Investigators say the dual bombs, which exploded 12 seconds apart Monday, were designed to deliver vicious suffering.