Sentence 1: Jimmy was sitting on his homemade porch. 
 Sentence 3: Jimmy heard a groaning noise and decided to investigate 
 Sentence 4:  Just as he walked off of the porch, the entire thing crumbled 
 Sentence 5:  If he hadn't moved, he would have fallen and been hurt 
 Option 1: The porch was high up over his backyard. 
 Option 2: Jimmy was still sitting on it as it collapsed.