"We ducked underneath the desk in the E.R.," said Sue Hall, the nurse on call Sunday evening at St. John's Regional Medical Center in Joplin. "The pediatric crash cart, we found outside. We believe it was swept outside. The pressure in your ears was unbelievable."
Meanwhile at the hospital, Rob Pace held onto a door, trying desperately to keep it shut against the tornado's suction.
"I heard people talk about a building and how it breathes when it's on fire," he said. "It felt like that building was breathing and that door would move in and out."
He said he could feel the suction pulling him. "We just moved in and out with the door. The door never came open," Pace said. "It's an automatic locking door. Essentially I was leaning into that door and one of the pilots was basically holding on to me."
Dr. Ronny Smalling looked out the window and saw the tornado coming. "I went over to the window. The clouds were black," he said. "Everything was blowing. Wind was blowing and trees were blowing. Then I saw things fall out of the sky, like a roof top fell out of the sky."
Joplin, Mo. Tornado: 'I Really Thought That I May Die'
He said he could feel the tornado's suction in his lungs. "Almost like a drop in barometric pressure," Smalling said. "If you dive 30 feet in water, your ears are hurting. ... I really thought that I may die, [that] this may be my time."
"After it lasted 90 seconds, we heard the hail," Smalling said. He said that after the twister left, the hospital looked like an atomic bomb had detonated. "Every single floor was completely destroyed and all of the windows were blown out. We have no hospital right now."
"Before there were beautiful, 100-year-old oak trees in an established neighborhood," Smalling said. "As far as I could see to the west and as far as I could see to the east, at least a mile wide, there was nothing but dirt, mangled trees and cars, and the fire trucks began to roll in."
ABC News staff contributed to this article.