A reporter covering the race
David Abel was covering the race for The Boston Globe when the bombs went off. "When I opened my eyes and realized what was going on, I saw ... what was clearly the worst thing I've ever seen in my life."
A marathon runner
Tim Kriens, of Boyertown, Pennsylvania, came across the finish line only a couple minutes before the first of the two explosions on Boylston Street. "It almost sounded to me like a loud mortar when I was in Vietnam."
Carlos Arredondo is the man in the cowboy hat. The one in the infamous picture, racing alongside a gravely injured young man, Jeff Bauman, whose legs were blown off in the blasts. Arredondo, of Roslindale, says the whole time he was working to save the young man, he was thinking of his own two sons who both died tragically in recent years. "I don't consider myself a hero."
A medic in the tents
More than 260 people were injured in the blasts. Kim Giroux, a nurse from Tewksbury, was volunteering in the medical tents that day. "We went from triaging people with blisters, and then all of a sudden we had to shift into a field hospital."
A runner who didn't finish
One in four runners had not finished the marathon when the bombs exploded. Morgan Burke, of Boston, was made to stop just a half mile away from the finish line. "We just couldn't keep running; we had no idea what was going on."
A journalist asking questions
Bruce Gellerman, a WBUR reporter, was on the streets trying to find out what was happening.
Like hundreds of others that day, Lauren Healey, of Springfield, and John, of Cambridge, were cheering on runners near the finish line when the bombs exploded. "You could feel it in your chest ... and then it was just disbelief that this was happening."
A view from above
Christopher Harvey is an attorney in Boston. He looked down from his office onto Boylston Street. "Almost as if they were swimming up stream were dozens and dozens of traffic-green jacketed policemen, just heading right into that scene."
Massachusetts Gov. Deval Patrick spoke on the evening of the bombings, when very little was understood about what had taken place or who might be responsible for the violence that day. "We're going to get through this."
A chief of surgery
The victims were rushed to several Boston-area hospitals. Dr. Bill Mackey, chief of surgery at Tufts Medical Center, oversaw the rush of victims who were brought to his hospital that day. "We have some pretty bad injuries."
A daughter of the wounded
Rebecca Roche was running her first marathon that day in Boston. Hours later, she was at Tufts Medical Center at the bedside of her mother, Beth, whose kneecap was fractured in the explosions. "I turned and saw the black smoke and it was coming from right by a Marathon Sports, which is where I knew my family and friends were waiting."
An emergency room doctor
Many of the critically injured were brought to Boston Medical Center. Dr. Ron Medzon is an emergency room doctor at the hospital. "It was just one after another after another ... every single person had a limb-threatening injury, life-threatening injury."
A veteran photographer
John Tlumacki, of The Boston Globe, has photographed more than 20 marathons. When the bombs went off, he ran straight into the smoke. "I have to communicate with my eyes, I have to tell the story with my camera."
Krystle Campbell's mother
Krystle Campbell, 29, was one of the three people killed in the bombings. She worked as a restaurant manager and is remembered by family and friends as joyful and outgoing. Her mother, Patty Campbell, made a tearful statement to reporters outside her home in Medford the next day. "She was a wonderful person. Everybody that knew her loved her."
Martin Richard's principal
Martin Richard, 8, was the youngest victim. He lived in Dorchester and was a student at the Neighborhood House charter school. Kevin Andrews, the headmaster, remembers Martin as the sweet kid that we see in pictures. "Very, very compassionate."
The Richard family's neighbor
Jane Sherman lives next door to the Richard family in Dorchester. "Nobody should have to lose a child."
A voice of the city
Author and Boston native Dennis Lehane says the bombers picked the wrong city to go after. "This is when you know that the terrorists lost. Immediately. When you saw those people, civilians, running toward the blast."
A lifelong Bostonian
Ray Magliozzi hosts NPR's Car Talk with his brother Tom. Born in Cambridge, educated at MIT, with a studio in Harvard Square, they are lifetime Boston guys. "There was a lot of courage displayed on Monday ... I guess I'd have to call it reckless bravery."
A marathon legend
Bill Rodgers, four-time Boston Marathon champion, says the race shows the strength of the American people. "I saw that 70-year-old runner fall at the finish line when the blast hit ... he got up and he finished the race."
Scott Poole is a poet and long-distance runner. The bombings inspired him to write “To Run – A Prayer for Boston."
Lu Lingzi's classmate
Lu Lingzi, 23, was a graduate student from China studying at Boston University. She was known to love food and cooking. With no family in the country, Chinese students at BU took it upon themselves to try to find Lu on the day of the bombings. Shuang Guo, a classmate, says they went all around the city in search of Lu before being notified of her death.
Mayor Thomas Menino called it a "good morning," as he spoke at Thursday's memorial service for the victims of the bombings. "I'm telling you, nothing can defeat the heart of this city. Nothing. Nothing will take us down, because we take care of one another."
President Obama visited Boston on Thursday to attend the memorial service. He addressed the wounded directly, saying, "Know this ... we will all be with you as you learn to stand, and walk, and, yes, run again. Of that I have no doubt, you will run again."
The Boston Children's Chorus performed an emotional rendition of "Up to the Mountain" at the interfaith service.
The FBI appeal for help
Richard DesLauriers, special agent in charge of the FBI's Boston office, held a press conference on Thursday afternoon to announce the release of photos and video of two suspects in the bombings. "They are identified as Suspect 1 and Suspect 2. They appear to be associated. Suspect 1 is wearing a dark hat, Suspect 2 is wearing a white hat."
A slain officer
Sean Collier, a 26-year-old MIT police officer, was fatally shot on campus Thursday night, allegedly in a confrontation with the marathon bombing suspects. Law enforcement officials have acknowledged the possibility that the release of the suspect photos may have triggered their violent rampage that night. Collier is remembered as a dedicated officer and a beloved presence at the university. A resident of Somerville, Collier is mourned by Mayor Joseph Curtatone, who says he'd planned to bring him on to the city's police force very soon. "I was about to appoint him ... we were excited at the prospects of having him come back."
Shortly after the shooting at MIT, police received reports of the armed carjacking of a Mercedes SUV in Cambridge. The police pursued the vehicle and, in the early hours of Friday morning, around 12:50 am, caught up with the two suspects in Watertown. The suspects engaged the police in a gunfight, which ultimately led to the death of Suspect 1. Michael John, a Watertown resident, saw much of the action from inside his home. "There were two different gun battles going on at once."
Suspect 2 managed to flee the scene by driving through the officers and over Suspect 1 - reportedly inflicting the fatal injuries that resulted in his death. The Boston police scanners give a sense of the tense atmosphere as Suspect 2 remained at large.
The suspects identified
The two suspects were identified as the brothers Tamerlan and Dzhokhar Tsarnaev of Cambridge. Early reports that the surviving suspect, Dzhokhar, 19, might be involved in the bombings were met by disbelief from many of his friends. The nephew of WBUR's Robin Young attended high school with Dzhokhar at Cambridge Rindge and Latin and spoke to his aunt just shortly after learning that his friend was a suspect. "He was one of the leaders on the sports team ... just one of the nicest kids you could know."
The city shut down
At 8 am Friday morning, with a massive manhunt still underway, Gov. Patrick asked that people stay in their homes with their doors locked in Watertown, Cambridge, Waltham, Newton, Belmont, and Boston. He also suspended service on the MBTA.
At 6:10 pm Friday, Gov. Patrick lifted the shelter-in-place order. A Watertown resident stepped outside and noticed a disturbance to the tarped boat in his backyard. A helicopter equipped with a thermal camera confirmed there was a live body inside. At 8:45 pm, police announced they had the suspect, Dzhokhar Tsarnaev, in custody, as WBUR's David Boeri reported on the air.
Residents in Watertown cheered the police.