Example 2: So many trees were wiped out in the fire.
Explanation: wipe out can be used in many different ways.
In example 1, wipe out means fall. When used this way, wipe out is a phrasal verb to describe a fall off of a movie object such as a surfboard or skateboard and is commonly related to sports. This expression is often informal.
In example 2, wipe out means destroy. When used this way, wipe out is often used in the passive voice. Ex: The city was wiped out by the fire. This is often used to describe very serious situation with large scale destruction.
This idiom can be found in the book LSI Reading Savvy, 1st Edition. This book is used to teach Level 5 Reading/Vocabulary at LSI schools. For more information visit:idiomstudy.blogspot.com