Head injury caused by underwater explosion of a firecracker

✓ A firecracker exploded in contact with the skin and within 6 inches of the base of the skull of a young man while he was swimming underwater. The resultant severe head injury and death appeared to be directly related to the underwater explosion. Reconstruction of the mechanics of this injury indicates that when the head is subjected to impact energies between 440 to 1800 in.-lb and impact impulses between 1.8 to 3.5 lb/sec, both skull fracture and brain injury can occur.