The homemade bombs that ripped through the crowd at the finish line of last year's Boston Marathon, killing three people and injuring 264, showcased the city's medical talent but also taught valuable lessons in responding to a mass disaster.
By all accounts, Boston's hospitals performed well after the attacks on April 15, 2013. While many of the wounded lost limbs and a large amount of blood, all who made it to a hospital survived.
Looking back, a year after their hospitals were packed with blast victims, Boston officials have tweaked how they prepare for a disaster, now requiring city emergency medical personnel to carry tourniquets and developing a standard method for one city agency to track disaster victims in hospitals.
The new techniques will be in place by this year's race, set for April 21, with 36,000 runners taking part and tens of thousands of spectators expected to line the 26.2 mile course.
"This was worth more than 1,000 drills," said Dr. Eric Goralnick, medical director of emergency preparedness at Brigham and Women's Hospital, which received more than two dozen bombing victims. "A real event highlights real shortfalls and real successes like no other. And, after the marathon, every health-care provider became a champion of emergency preparedness."
A variety of factors contributed to the survival rate last year. Hundreds of police and medical personnel were working the race, allowing for a quick response. Hospitals hold disaster scenario drills dozens of times a year, making sure teams are able to work quickly and fluidly in a crisis.
The city's compact size made for speedy transport to its six level-one trauma centers, where doctors and nurses stabilized victims, set bones, and performed necessary amputations.
A key element, experts said, was the use of tourniquets, sometimes improvised from clothing. They stopped excessive bleeding from wounds to victims' feet and lower legs caused when the nail-filled pressure-cooker bombs exploded at ground level.
The wars in Iraq and Afghanistan, where U.S. soldiers have often encountered improvised explosive devices, illustrate the value of tourniquets. City officials are applying that knowledge more widely as tourniquets become standard equipment for Emergency Medical Services staff.
"Every clerk, cook and trombone player has a tourniquet and if we'd had more that day, patients would have gotten to us in better physiological shape," said Joseph Blansfield, trauma program manager at Boston Medical Center who served as a combat nurse in Iraq. "Some were on their last drops of blood."
The throngs of patients who arrived with no identification underscored flaws in electronic tracking systems where the victims' strings of identifying numbers started to look alike.
On the day of the bombing, the biggest weakness, however was in pushing information to one central agency responsible for tracking all data from all hospitals to help reunite families.
The most vivid illustration of that occurred when relatives of Krystle Campbell, who was killed, were initially told she had survived, only to later learn it was her friend who was alive.
Staff from Boston's hospitals have since created a new single-page disaster record, including a checklist to capture specific aspects of care that might be missed in a disaster and record identifying features like hair color, tattoos and piercings.
"It is important that we ID people better and push that to the next level quickly," said Maureen McMahon, director of emergency management at Boston Medical Center. "It was hard to look people in the eye and say we don't know where your loved one is."
As victims slowly adjust to life without limbs, a ballroom dance instructor's story inspired a Massachusetts Institute of Technology biophysicist who is a double amputee to return her to the dance floor with a specially designed bionic leg.
"It was 3.5 seconds between the blasts that took Adrianne Haslet-Davis off the dance floor, but within 200 days we brought her back," said Hugh Herr, head of the Biomechatronics research group at MIT's Media Lab. Last month, Haslet-Davis performed a 30-second rumba onstage at a conference where Herr was speaking.
Cautioning that the dancing leg is still in research and not yet a product, Herr said bionic limbs are far better than conventional prosthetics in returning victims to everyday activities.
This month he launched the No Barriers Boston Fund to raise money to pay for Boston Marathon bombing survivors to receive bionic limbs designed for athletic use that are often not covered by regular insurance.