UPDATED BREAKING NEWS: One Boston Marathon Bomber Is Dead, One Still On The Loose

One of the two bombers in the Boston Marathon bombings is dead - the other is on the loose. .

Federal authorities say the suspects seen in the FBI photos circulated yesterday robbed a convenience store last night, and then shot and killed a transit police officer in order to get his vehicle.  A chase and shootout ensued.  The suspect seen in photos with a dark ballcap was killed by a combination of what is being described as quote "blast injuries and too many gunshot wounds to count".  Police say the pair were throwing explosive devices at officers as they led them on a car chase.

The suspects are brothers from Chechnya in Russia.  They are Muslim.  One of the suspects posted on his Facebook page that he has no American friends and "I don't understand these people".  Chechnya is predominantly Muslim and has been locked in a battle with Russia to be a separate country.

Boston Police Commissioner Ed Davis says the suspect on the run is a "terrorist who came here to kill people."  Boston has been shut down with police telling people to stay in their homes and not to open businesses so there is no chance of a hostage situation or another bomb going off and killing more people.

The last suspects father says he has been urging his son to turn himself in peacefully, but if he is killed, "all hell will break loose".  Police are worried that there might be other bombs planted by people who were helping the brothers stay underground for the past few days.

We will update as more information becomes available.