The numbers are staggering: more than 170 people injured. Many have metal pellets and shrapnel lodged in their bodies.
Legs are so badly injured, some amputations happened immediately, as surgeons try to save the limbs of others.
Long time Houstonians might remember a similar tragedy that happened right here in our city.
The year was 1959. A man walked into Poe Elementary School in Southwest Houston with a suitcase full of dynamite, killing six people.
Earl Fogler, now 60, was only seven when he was an innocent victim of that bombing.
He told Local 2, "Back when it happened to me, it was a rare occurrence. It was pretty far between. But now it seems to be more often."
20 people, many children, were injured in the Poe bombing.
Earl said, "I tried to get up and walk and realized I couldn't." His right leg had to be amputated below the knee.
Dr. Danielle Melton, Director of the Amputee Program at TIRR Memorial Hermann told Local 2, "Losing a limb, I tell my patients all the time, it's like losing a close family member. You go through the same grieving process."
Dr. Melton said amputation can lead to multiple operations and months of rehab.
She explained, "The body can be also complicated by whatever the outcome of the final amputation (is), whether or not there are skin grafts or muscle flaps and whether or not it heals appropriately.
So that's a part of it and being able to fit a prosthesis with those complications, but the psychological part of it is something that we deal with long term."
Earl now works in prosthetics and helps amputees reach their goals.
He said, "They're the motor. They're the one that makes the prosthesis work. So they have to want to do it. They have to have the motivation and want to get back to doing what they're wanting to do."
As doctors in Boston work to give the bombing victims the best medical care possible, post traumatic stress disorder can often be the biggest hurdle to overcome.