In the deadliest disaster at Mount Everest, 13 Sherpa guides were killed and some other people were believed missing after an avalanche swept a route used to ascend the world's highest peak, NBC News reported. The guides had gone early in the morning to fix ropes for hundreds of climbers when the avalanche hit them just below Camp 2 in an area known as "popcorn field." NBC News crews were on site preparing for a production for the Discovery Channel. All NBC News employees are safe.
