Simplify the following text for a Grade 8 native English-speaking person.
Original: In October 1976 , an arson caused the destruction of four subway cars and damage to Christie station , resulting in the closure of the Bloor-Danforth Line for three days , and the by-passing of Christie station for some time afterwards for repairs .
Simplified: In October 1976 , an arson ( a fire set on purpose ) destroyed subway cars and damage to Christie station . This caused the closure of the Bloor-Danforth Line for three days , and closed Christie station for some time for repairs .