Rescue teams and military helicopters are searching for hundreds of missing people after flash floods on the Nepal-China border. The torrent of water and mud several stories high swept through communities Wednesday after rock and a glacier collapsed in the Himalayan region. Videos showed people running ahead of the floodwaters that washed out buildings and bridges. More than 390 people were killed and more than 1,400 are missing, including hundreds of foreigners and pilgrims. Hundreds of others have been displaced across the Himalayan region. The steep slopes and lush valleys below the Himalayan mountain range are especially vulnerable to flooding and landslides.