steel door

The collision was immense. My skull slammed into something hard and my neck jarred and everything flashed black and then I was stumbling forward and falling, the bodies attached to each forearm cushioning the blow. Without hesitation, my adrenaline in overdrive, I loosed my arm from Black Beard and rolled to my back, pulling Sprinter over top of me. Using my heels, I scuttled backward across a concrete floor into complete darkness. I was in. The bright orange light pouring through the smashed doorway obliterated any view of the warehouse’s insides. Through that doorway, I heard fast-approaching footsteps.

...

My head was still ringing from the collision with the door. I headed over to where it lay flat on the warehouse floor.

“Fucking shite mate,” said Gow, eyeing the door for the first time. “That door opens outward.” I looked down, checking the hinges. Sure enough, the door was still locked shut in its frame. The collision had blasted both door and frame out of the concrete block wall. The weakpoint had been the concrete, not the door. No wonder my head hurt.
-Sledge vs. The Labyrinth, pg. 158-161