Sentence 1: The sirens started going off. 
 Sentence 3: They never thought a tornado would actually hit 
 Sentence 4:  The roof started coming off the school 
 Sentence 5:  Luckily no one got hurt 
 Option 1: The children went out into the hallway. 
 Option 2: Lucky for them it was just a test as it was a sunny day.