Head-first free falls of 30 children, 1-10 yr old, and one adult, 21 yr old, were studied to determine fall circumstances and injuries sustained. The falls of six children and one adult were simulated using the MVMA Two-Dimensional Crash Victim Simulator computer model. The data show that head-first falls of children onto rigid surfaces from heights as low as 2 m can result in serious injuries. Conservative head injury tolerance limits are estimated to be 200-250g for peak head acceleration.