Threat of debris dam burst slows rescue efforts Rescue operations following the devastating flash flood in Nepal and Tibet are proceeding cautiously amid fears that a barrier lake formed by the original avalanche could burst, threatening further flooding Kathmandu NEPAL CHINA Detail 150m Glacier: Lower part collapses, sending ice and rock down valley Langtang Lirung Barrier lake: Over 2.5 million m3 of water Nepal Estimated depth 50m Debris dam: Formed at confluence of rivers Rainfall has continued to loosen and destabilise soil and ​rock Lhende Khola River Deluge travelled first 22km at average speed of 193km/h. Over 90,000 people affected Source: BBC, Reuters, CGTN Picture: Google Earth © GRAPHIC NEWS