Complex sentence: On 26 April 1868, two trains collided head-on at the station as a result of a signaller's error which caused an arriving train to be misrouted to the platform where a second train was stood awaiting departure.
Split into simpler sentences: On 26 April 1868, two trains collided head-on at the station. This was the result of a signaller's error which caused an arriving train to be misrouted to the platform where a second train was stood awaiting departure.