Ethiopian Airlines Flight 702 headed from Addis Ababa to Milan signaled "Squawk 7500," a radio frequency that indicates hijacking. The plane passed Rome, where it was supposed to stop, and Milan, where the flight was scheduled to end, eventually landing in Geneva. @matthewkeyslive posted audio purporting to be someone on the plane requesting asylum in communications with air traffic control in Geneva. Jaunted.com reports asylum was negotiated between Swiss authorities (the ones available before 6am local time), the pilots, and the hijackers while the plane burned through its fuel over Lake Geneva. It finally landed at Geneva around 6am local time, and the airport remains closed with flights diverted to Zurich.
Twitter spent the last few hours pointing out social media was on ET702 news while the mainstream media wasn't, though it appears, according to Twitter, to be being picked up by cable news outlets, including BBC and CNN. It doesn't yet appear to be on any of the major US news websites, including CNN.com. Also via Twitter, a press release from Ethiopian Airlines claiming passengers and crew were safe was pulled from its website. The pilots may have exited via the windows.
The Swiss, incidentally, recently voted to restrict the country's immigration rules.