Field trip to nowhere. (Thinkstock)

Parents of students at John Adams Elementary School in Corona, California, were terrified a couple of weeks ago to receive automated phone calls telling them their students were not in school. The school uses a program called Blackboard Messaging that automatically lets parents know when their kids are absent. Due to a combination of human and computer error one morning, it left a message for parents of all 717 students

Sources: Time | The Press Enterprise