Oops - this case was scheduled to post last Thursday but didn't trigger.
A child is brought in by ambulance as a major trauma. He was hit by a slow moving car which pinned him against the wall. When EMS found him, his chest was pinned against the bumper. There was no injury at the neck. He is stable on your primary survey of airway, breathing, circulation, disability, and exposure. On your secondary trauma survey, you note bilateral conjunctival hemorrhage, facial edema, ecchymoses, and petechiae on the upper chest and face. Fortunately, the prognosis for this is generally favorable.
Challenge: What happened?