This email was supposed to prevent the Brussels metro explosion. But it was sent to the wrong address.

It was 9:07 a.m. on March 22 when Belgian police's directorate of operations sent out an email ordering the closure of the Brussels metro. Earlier that morning, at around 8, there was an explosion at Brussels Airport. It took federal police almost an hour to conclude that their city was under attack and that all metro lines […]

Source: http://www.washingtonpost.com/blogs/worldviews/wp/2016/05/12/this-email-was-supposed-to-prevent-the-brussels-metro-explosion-but-it-was-sent-to-the-wrong-address/