Abstract: Safety apparatus for use with a trailer of the type having brakes is shown. If the latch mechanism on the trailer hitch is not properly closed, the brakes on the trailer are engaged thereby preventing the trailer from being towed. In addition, a warning device, such as a audible alarm and/or a light, signals the operator of the unlatched condition of the trailer hitch. If the latch mechanism becomes disengaged while the trailer is being towed, the warning device signals the operator and the brakes are engaged to stop the trailer. In a preferred embodiment actuation of the brakes is delayed to allow the operator time to stop the vehicle. The apparatus of the present invention may conveniently be mounted on the trailer so that it will be functional with any towing vehicle.