Mourning, resolve and quest for answers after deadly Boston Marathon bombs

Updated 7:18 AM EDT, Wed April 17, 2013

Story highlights

NEW: Photos shows parts of a pressure cooker, backpack and pellets

An 8-year-old boy, 29-year-old woman and grad student from China die

Scores more are injured in the twin blasts, helped by medical staff and others

Authorities say they don't have any suspects or a motive for the attack

(CNN) —  

A 29-year-old woman, remembered by her mother for her “heart of gold.” A Boston University graduate student from China who’d gone to enjoy the marathon’s finish with two classmates. An 8-year-old boy, cheering on runners with his family.

All of them, gone.

Their lives were snuffed out by twin blasts at the tail end of Monday’s Boston Marathon. Thirteen others – out of 183 hospitalized – had limbs amputated, according to hospital officials. The question is: Why?

The victims: Promising lives lost in tragedy

More than a day later, authorities don’t have an answer. Unlike after the September 11, 2001, attacks, no one claimed responsibility for this terrorist attack. No one had been identified as a suspect. The attack came out of nowhere, with no threat. Just horror.

As Richard DesLauriers, the special agent in charge of the FBI’s Boston office, put it Tuesday afternoon: “The range of suspects and motives remains wide open.”

The two identical pressure-cooker bombs – each with the capacity to hold six liters of liquid, according to a Boston law enforcement source – blew up seconds and a short distance apart on Boston’s Boylston Street. They contained BB-like pellets and nails, the FBI’s DesLauriers said, causing even more damage.

Photos obtained by CNN, which were in a bulletin sent to federal law enforcement agencies, showed parts of a pressure cooker, a shredded black backpack and what appear to be metal pellets or ball bearings. Such evidence – including a partial circuit board – are headed to an FBI facility in Quantico, Virginia, where authorities will try to determine how the devices worked and cull out clues identifying the person or persons responsible.

More on the investigation into the bombings

Whatever investigators find, whenever they find it, it won’t take away the pain. Scores who are not grieving loved ones are faced with a lengthy physical recovery. There’s the psychological battle as well – living with the memories of the deafening blasts, the carnage, the fear as they searched for loved ones.

Ron Brassard was one of them. One second, he was laughing and smiling. The next second, there was a roaring blast, originating from about 10 feet away, and he looked down to see a “puddle of blood.” He later discovered a “chunk of the leg was just not there.” His wife was hospitalized, too, and a friend lost both her legs.

Brassard told CNN’s Anderson Cooper he is angry. But he’s also not about to let this terror change him, any more than it already has.

“You can’t let people control your life like that,” Brassard said from his hospital bed. “You just can’t.”

Hundreds run toward carnage to help

The pressure wave from Monday’s explosions in Boston’s historic Copley Square whipped the once limp international flags straight out, as if they were caught in a hurricane.

Some runners said they thought the first blast was a celebratory cannon. By the second, there were no such illusions.

The scene on the ground was sheer horror. Blood and unconscious people were everywhere.

So, too, were people who went to help.

Boston heroes run to help

Some were spectators, like Carlos Arredondo. An affiliate of the Red Cross, he tended to a man who’d lost two of his limbs.

Dr. Natalie Stavas, a pediatric resident at Boston Children’s Hospital, was near the home stretch of the r