Simplify the following text for a Grade 9 native English-speaking person.
Original: When Harry 's parents were murdered by Lord Voldemort , they left behind a large pile of wizard 's gold , used as currency in the world of magic , in a vault in the wizarding bank , Gringotts .
Simplified: Harry 's parents left behind a somewhat large pile of wizard 's gold , used as currency in the world of magic , in a vault in the wizarding bank , Gringotts .