A teenage boy had a plan.
According to authorities in Waseca, Minnesota, John David LaDue, 17, was going to kill his family, start a diversionary fire, set off bombs at an area school, kill the resource officer there and then shoot students.
CNN does not usually publish the names of minors charged with crimes but is naming him in this case because his name has been widely reported in his community.
Frighteningly, police say, LaDue had the resources to carry out such an attack.
But because of watchful eyes, he is now behind bars.
"This case is a classic example of citizens doing the right thing and calling the police when things seem out of place. By doing the right thing, unimaginable tragedy has been prevented," the Waseca Police Department said in a Thursday statement.
Police were tipped off to the case two days earlier. Chelsie Shellhas called them about someone acting suspiciously at a storage facility.