1.   But instead of smashing into the oncoming northbound traffic, the vehicle slammed into flexible steel cables installed to prevent crossover accidents.

2.   College officials, meanwhile, asserted that the camera had been installed to prevent burglaries.

3.   In three incidents, pilots changed course after they were alerted by a cockpit device installed to prevent midair collisions.

4.   It said a new system had been installed to prevent future violations.

5.   Extra guards have been hired, searches for courthouse visitors introduced and video cameras installed to prevent incident.