The blast ripped Joseph "JP" Norden's right leg from his body.
The Wakefield, Mass., man's body was burned and wrecked with shrapnel. In the hours since Boston firefighters wrapped a tourniquet tight around the amputation and he was raced to Brigham and Women's Hospital, "JP" has undergone two surgeries and was intubated.
But when doctors removed his breathing tube this afternoon JP's first question to his mother with his eyes filled with tears was: "Where's Paul?"
Liz Norden fought back her own tears, squeezed her oldest son's raw, bruised hand and told her eldest son, 33, "Paul's okay. He's worried about you."
Paul, 31, is alive but not at all okay. He also lost his right leg and suffered serious burns. He, too, was wounded by flying ball bearings, his face swollen with bruises.
The brothers were spectators near the finish line waiting to cheer on their friend, Somerville firefighter Mike Jefferson. After the first bomb went off the brothers shielded the firefighter's mother, daughter and aunt and took the brunt of the explosion.
As an ambulance tore towards Beth Israel Hospital with Paul, he called his mother.
"Mom, I'm hurt real bad and I can't find JP," he told her.
But all he cared about was finding his brother.
"I was in shock,'' Liz Norden told ABC News exclusively. "The ambulance driver told me he was in critical condition and we had to get to the hospital right away. All he kept asking about is his brother. And we couldn't find him. I didn't know if I lost both my boys."
It would take hours for the family to learn that JP was also critically wounded, but alive. JP's right leg was severed and his left leg badly mangled. Paul's girlfriend Jackie was severely burned. One of the brothers' close friends lost both legs, his right leg gone from the hip; the left from the knee.
"This is like a nightmare,'' Liz Norden told ABC News in an exclusive interview as she walked from one ICU unit to another, back and forth trying to comfort her two sons.
Her youngest boy, Jonathan, and two daughters, Colleen and Caitlin, were at her side.
"I would give both my legs for them,'' said Jonathan, 28.
"My brothers are tough guys but they have soft hearts,'' said Caitlin 24.
At JP's beside, Liz Norden stroked his bloodied, bruised face.
Other family members held vigil at Paul's bedside. Paul reached for his mother's hand but couldn't speak. His eyes darted from one family member to another searching for answers.
His mother knew the question and comforted him before he went into another surgery at Beth Israel to clean his wound and stave off infection from the burns. "Don't worry,'' Liz told Paul. "JP's okay. Jackie's okay. I love you. I love you so much."
Both Paul and JP underwent surgery today to clean burn wounds and to remove ball bearings and nails from their bodies, many of them embedded in their forearms, the family said.
Doctors have said that many of the patients have been found with shrapnel in the bodies and have cited nail-like items that they believe were packed into the bomb.