Three ominous theories for what happened to MH370

1. It was an electrical fire – This theory was first put forth by pilot Chris Goodfellow, and has enjoyed wide discussion and dissemination online. Goodfellow says he thinks the disappearance was sparked by a small electrical fire in the cockpit, which could have shut down communication and forced the pilots to turn the plane toward a nearby airfield. The smoke then overtook the crew, and the plane kept flying until it eventually ran out of fuel and crashed over the ocean. This theory matches some of the circumstances investigators discovered, including that the plane took distinct and purposeful turns before disappearing.

2. The pilot crashed the plane – Given what we now know happened over the French Alps, when an apparently suicidal Germanwings co-pilot intentionally crashed a passenger plane into a mountain, this theory is not altogether far-fetched. This theory proposes that one of the pilots of MH370 – with enough training to know how to shut off the transponders – intentionally downed the plane either as a terrorist act or as an act of suicide. ABC News reports that there is nothing in the pilot's background to suggest this is what happened.

3. The US shot it down – This theory really picked up steam after a computer expert claimed to have hacked a passenger plane's controls. The theory goes that the U.S. discovered the airplane had been hacked remotely, and fearing another 9/11-like event, shot the plane down before it could be turned into a bomb. For online theorists, Reunion's proximity to a U.S. military air base on British-controlled Diego Garcia bolsters this theory. Variations on this theory include the plane being hijacked and crashing during an attempted landing.

Have a theory of your own? Weigh in in the comments.