Simplify the following text for a Grade 9 native English-speaking person.
Original: The war overtook Young 's career again in February 1943 when he was one of a number of chief constables seconded to the War Office Civil Affairs Training Centre and attended the first course for senior officers .
Simplified: In February 1943 Young was one of the chief constables sent to the War Office Civil Affairs Training Centre for the first course for senior officers .