Complex sentence: The Securitas depot robbery was the largest cash robbery in British history, that took place on the evening of 21 February 2006 from 18:30 GMT until the early hours of 22 February.
Split into simpler sentences: The Securitas depot robbery was the largest cash robbery in British history. It took place on the evening of 21 February 2006 from 18:30 GMT until the early hours of 22 February.