Roughly 68 minutes into Sunday\'s practice session, the San Francisco 49ers\' workout came to an abrupt halt as defensive end Tarron Jackson went to the ground and didn\'t get back up.
In what appeared to be a standard running play, Jackson was being blocked by offensive tackle Isaac Alarcon when he went down. Teammates quickly shouted for the training staff as Jackson was briefly motionless before moving his hands. His teammates dropped to a knee, and the team and sideline went silent for the next six minutes as a cart brought out a stretcher for Jackson. He was taken off the field roughly seven minutes after the injury, and an ambulance took him to Stanford Hospital about 21 minutes after he first went down.
Via ESPN.com