Abstract Due to simultaneous horizontal and vertical displacement during vertical evacuation. the consequences of stampede congestion accidents can be more severe. Generally. pedestrians trigger a synchronization mechanism at some point during the vertical evacuation process. https://www.spidertattooz.com/The-Creme-Shop-X-Hello-Kitty-Pure-Cure-Strawberry-Milk-Toner-Klean-Beauty-p14481/