In the 2014 film The Amazing Spider-Man 2, there's a sequence in which a villain disables the city's power grid. All over town, stuff loses power... including the local airport and its air traffic controllers. This is a problem because there are currently two planes inbound, on courses that will cause them to collide with each other in midair unless the tower can warn them in time!
Luckily, Spider-Man finds a way to defeat the villain and the ATC gets their power back just in time to radio the planes to change course, and they miss each other by an extremely narrow margin.
Putting aside for the moment the question of whether or not a real ATC would have their own independent backup power source, how realistic are the two premises of this crisis?
1) That two airplanes would be inbound towards a major airport on courses that would cause them to both occupy the same position in 3D space at the same time, and
2) That neither pilot would actually notice this until either the tower told them or something suddenly goes CRUNCH! Do commercial jet liners not have their own radar at the very least? (Heck, my car has little radar emitters that warn me if something is too close!)