A solar storm almost caused a worldwide blackout in 2012
Solar storms or, more accurately, coronal mass ejections are events during which large amounts of plasma and an accompanying magnetic field are released by the Sun. If a CME were to reach the Earth’s magnetic field, it could cause serious damage to electrical power grids, among other issues.
In 2012 there was an abnormally strong solar storm that could have damaged electrical equipment all around the world, but fortunately, the area of the Sun from which it came was pointed away from our planet. We were saved from catastrophe through sheer luck. Scary, right?