(NBC NEWS) - Heartache filled the Boston commons as hundreds gathered to grieve and try to draw some kind of strength from being together.
Clinging to one another after two blasts that tried to rip them apart.
Simultaneous explosions near the finish line of the Boston Marathon that injured more than 170 people and killed three.
The youngest victim is 8-year-old Martin Richard ."To know that little boy will never come home again. Its kept me up at night and it will probably keep me up more nights," said Dan Aguilar, a Richard family neighbor.
Martin is being remembered in his home town of Dorchester, while in Boston a grieving mother tries to understand why her 29-year-old daughter Krystal Campbell is gone. "She had a heart of gold, always smiling. couldn't ask for a better daughter. I can't believe this has happened," said Patty Campbell, mother of Krystal Campbell.
Disbelief and pain is what is fueling the determination of the investigators.
"We'll continue to work tirelessly around the clock...Forces of the US are working hard to find those responsible," said Richard DesLauriers of the FBI.
The FBI released the first pictures of the devices used in the attack. Improved pressure cookers, packed with metal shrapnel including; BB'S and nails to maximize their impact.
More than 70 remain in Boston hospitals still struggling to survive after the attack.
"They have extensive wounds and burns. most suffered burns from explosion, and they also have shrapnel and metallic objects that tore their skin," said Dr. Gorge Velmahos of Massachusetts General Hospital.
President Obama will travel to Boston on Thursday for a inner-faith prayer service. "We're going to uncover whoever it is that was responsible for yesterday's cowardly act," said Obama.
As a community and nation continue to grieve.