Carl Smith collided with a concrete lamp-post while skating and suffered a skull fracture that caused a coma. When he failed to regain consciousness, his parents on August 8 consented to his life support machine being turned off.
Carl's coma was caused by the collision.
( z1 cause :ARG0 ( z2 collide ) :ARG1 ( z3 coma :poss ( z4 person :name ( z5 name :op "Carl" ) ) ) )