(CNN) Of all the Boston Marathons he's worked and he's done a half dozen of them Stephen Segatore figured this one would be pretty easy.
The weather was cool so the runners probably wouldn't be at much risk for heat stroke or dehydration. Maybe he'd help people with muscle cramps or twisted ankles but not much more than that.
Segatore a nurse for 18 years started his day Monday with the elite athletes in Medical Tent B toward the start of the race. Once those runners were well on their way he transferred to Tent A at the finish line. He was talking to a group of doctors and nurses when they heard the first explosion.
Instantly a team meant to tend to the achy and exhausted became a trauma team. The first step those who didn't have experience with trauma stepped aside. Those with experience dashed out in the direction of the noise.
Segatore who works in the intensive care unit at nearby Tufts Medical Center had experience.An injured man is loaded into an ambulance on Monday April 15 after two bombs went off near the finish line of the fabled Boston Marathon. Read our developing news story and follow up to the minute reports on CNN.com's This Just In blog. A man comforts a victim on the sidewalk at the scene of the first of two apparent bombings near the finish line of the Boston Marathon. A second explosion goes off near the finish line. Police officers with their guns drawn hear the second explosion down the street. The first explosion knocked down 78 year old runner Bill Iffrig at the finish line. He got up a few minutes later and finished the race. A runner embraces another woman on the marathon route near Kenmore Square. Former New England Patriots offensive lineman Joe Andruzzi carries a woman from the scene. A victim of the first explosion is helped on the sidewalk of Boylston Street. An injured person is taken away from the scene in a wheelchair. A woman kneels and prays at near the finish line. People run down Exeter Street after the blasts. The explosions occurred around 2 45 p.m. about an hour after the first of the race's nearly 27 000 runners had crossed the finish line. Victims lie on the ground at the scene of the first explosion. A couple runs from the scene pushing a stroller. A runner reacts near Kenmore Square after the explosions. A man's blood stained feet hang outside an ambulance. A bystander who was injured in the first explosion is wheeled across the finish line while receiving medical attention from rescue workers. The second explosion goes off near the finish line. Boston police look at blown out windows. The bombs shook buildings sending people to seek shelter under tables witnesses said. Unclaimed runners' bags fill an area near the marathon finish. Women desperate to hear from loved ones are unable to get close to the site of the attack. Police and runners stand near Kenmore Square after the attack. Runners gather near Kenmore Square after the explosions. An EMT worker is transferred to an ambulance outside a medical tent in Copley Square. A SWAT team arrives on the scene. A runner sits near Kenmore Square after the attack. Runners who had not yet finished the race are stopped after the explosions. Victims are helped at the scene of the first explosion. A man in tears is helped at the scene on Boylston Street in Boston. Passersby put pressure on a victim's leg to try to stop the bleeding at the scene of the first explosion. Massachusetts State Police guard an area near Kenmore Square. Bystanders embrace near the finish line. Police officers gather on Newbury Street. Women and children are evacuated from the scene. Bomb squad officials check a possible suspicious device near the scene of the blasts. A woman is comforted after the blasts. Two injured women are taken away on stretchers. An injured woman is loaded into an ambulance. First responders load injured people into an ambulance. An injured man is prepared to be moved from a stretcher to an ambulance. An injured woman is placed on a stretcher. A runner is comforted following the attack. The Cambridge Police Department's bomb squad investigates unattended personal items left behind after the explosions. Bystanders check their mobile devices for news of the explosions. Carlos Arredondo who was near the finish line when the bombs detonated leaves the scene. A member of the bomb squad investigates a suspicious item on the road near Kenmore Square. A runner in a wheelchair is taken from a triage tent after the explosions went off. People comfort each near the site of the blasts. Racers and race officials stand by after multiple explosions near the finish line. Emergency personnel respond to the scene. Police and emergency crews tend to victims. An injured woman is carried away on a stretcher. A man lays on the ground after the incident. Officials watch as the first explosion goes off on Boylston Street in Boston. Spectators leave the bleachers after the explosions. Police inspect one of the blast sites. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 Photos Deadly attack at Boston Marathon Doctor 'We were ready for this' Runner Shock waves hit my whole body Witness Pool of blood in middle of store Is it possible to secure major events
I ran out and saw people who were missing legs and part of their face and part of their abdomen he said Monday evening. My training prepared me for what to do but nothing can ever really prepare you for what you see.
Segatore was one of a team of dozens of doctors and nurses who volunteered at Monday's Boston Marathon. They worked quickly to stop bleeding and start IVs so patients could get into ambulances and to hospital emergency rooms. They treated dozens of patients without proper supplies for severe trauma such as dressings and pain medications.
No one expects to work at the Boston Marathon and end up at a terrorist attack he said.
One of his first patients was a young woman he thinks maybe 20 or 22 years old whose abdomen was torn open. Her left leg was broken and facing the wrong way and she wasn't breathing. He and his colleagues did CPR on her and kept checking for a pulse but there was none. They stopped when they realized it was futile.
She became the first patient in their makeshift morgue.
Segatore and others checked her pockets for a wallet an ID a cell phone anything that would help them find her parents' names. There was nothing.
I still don't know who she was he said. She had blonde hair blue eyes the all American girl. She was probably a student somewhere in Boston.
I've seen people die all over the world but I've never been this upset or angry in my career Segatore said. This is the Boston Marathon. People come from all over the world and all of a sudden that world exploded on them.
Working alongside Segatore in Tent A was Jim Asaiante a nurse in the emergency room at the UMass Memorial Medical Center in Worcester Massachusetts. Asaiante didn't run out after the explosion. He has plenty of experience in trauma but as a veteran of the Iraq War he's also had plenty of experience with explosions.
I heard the first IED (improvised explosive device) and I know there's never one. The bad guys always set up two or three said Asaiante an Army captain who did an 18 month tour in Iraq in 2006 and 2007.
Another victim was brought into the tent a man with his calves and feet blown off and blood pumping out of his knees. Asaiante put a tourniquet on him started an IV and in 15 minutes the man who was screaming in pain was in an ambulance.
After the second explosion Asaiante ran out of the tent.
There was lots of bleeding shrapnel glass. It was mayhem he said. The injuries were very similar to Iraq.
Despite the chaos he said the work of the doctors nurses and EMTs was impeccable.
The most amazing thing was how everyone worked in tandem. They didn't even have to speak a word between each other he said. In 20 years of nursing this was the most amazing two hours of nursing in my life.