By Joe Cash and Ryan Woo BEIJING (Reuters) -Authorities moved more than 45,000 people in earthquake-hit Tibet to shelters in a massive rescue operation near the foot of the Himalayas, as they wound down the search in a high-altitude environment where the odds of survival were always slim.

Rescue workers in China ’s mountainous Tibet region are racing to reach survivors trapped under the rubble as night temperatures drop far below freezing point following a powerful earthquake.