Federal investigators believe an engineer's error rather than mechanical failure caused a train collision in Boston last year that injured 267 people.
Problems include failures within the system designed to prevent train collisions and escalators failing or breaking apart while in service.
It is designed to prevent certain types of accidents, including train collisions.
The first case of severe neck pain arising from a train collision was documented around 1919.
In 1982, a train collision resulted in 76 injuries, but no fatalities.
Nineteen people were killed in a train collision at Middletown, Ohio.
With 17 persons killed and 145 severely injured the train collision is amongst the most serious in rapid transit.
On 1 February 1964, it was the site of a head-on train collision in which 70 people were killed.
A good example is the train collision recently near Baltimore that killed 16 people.
On 28 February 1967, Stechford station was the scene of a train collision.
