Simplify the following text for a Grade 8 native English-speaking person.
Original: In 1665 , London was swept by a visitation of the plague , and then , in 1666 , the capital was swept by the Great Fire , which raged for 5 days , destroying approximately 15,000 buildings .
Simplified: In 1665 , London was hit with the plague , and then , in 1666 , the capital was burned for 5 days by the Great Fire , destroying around 15,000 buildings .