Catastrophic flooding along the China-Nepal border has triggered a massive search and rescue operation. A large wave, originating in the mountains, unleashed its fury upon communities, destroying infrastructure and carrying away vehicles and buildings. Hundreds of people are currently missing, raising fears of significant casualties. The disaster is impacting both locals and tourists, with reports indicating dozens of American citizens are among those unaccounted for. Authorities are scrambling to assess the full extent of the damage and coordinate relief efforts. NBC News correspondent Janis Mackey Frayer is reporting from the scene, providing updates on the unfolding situation.