The death toll from devastating flash floods in Nepal-Tibet has risen to 469, while 1,545 people remain missing on both sides of the border. Rescue teams are searching riverbanks and isolated settlements for survivors and recovering bodies swept downstream. However, concerns remain over a newly formed barrier lake near the source of the Bhote Koshi river system. Authorities fear that a breach could trigger another surge of water, worsening the disaster and hampering rescue operations. Nepalese security personnel have evacuated more than 800 people from the affected districts.