A motorized seat belt retractor configured to be activated in response to a signal generated by a dangerous state detection device indicating that a vehicle is in a dangerous state. The retractor is configured so that in response to the signal the retractor operates to retract a seat belt webbing prior to a collision thereby restraining an occupant positioned in a seat in the vehicle. The retractor is activated every time a signal indicating that the vehicle is in a dangerous state is received from the detector.