This study analyzes the dynamics of pedestrian crowds, focusing on the 2006 Hajj crowd disaster in Mina/Makkah. Using video recordings, researchers observed two sudden transitions in crowd flow: first from laminar to stop-and-go flows, then to "turbulent" flows, which caused severe trampling accidents. The study reveals that high-density flows can become unstable, leading to sudden pressure releases similar to earthquakes. These transitions are not well understood, but the research identifies key factors such as local density, velocity variance, and "pressure" as critical indicators of crowd instability. The "pressure" is defined as the product of local pedestrian density and velocity variance, and it helps predict critical crowd conditions. The study also shows that in extreme densities, pedestrian motion remains finite, and the crowd can develop irregular flows, leading to shockwaves and safety hazards. The findings have important implications for organizing safer mass events, as they allow for early warning systems and adjustments in crowd management. The insights from this study contributed to the successful organization of a safe Hajj in 1427H, with changes such as improved stoning capacity, better crowd flow management, and the removal of bottlenecks. The research highlights the need for further simulation models that can accurately predict crowd dynamics, especially in high-density situations. The study also emphasizes the importance of understanding the mechanisms behind crowd panics and the role of local conditions in determining crowd behavior. The findings have broader implications for other mass gatherings, as similar dynamics can occur in various crowded environments. The study underscores the importance of real-time monitoring and adaptive crowd control strategies to prevent disasters.This study analyzes the dynamics of pedestrian crowds, focusing on the 2006 Hajj crowd disaster in Mina/Makkah. Using video recordings, researchers observed two sudden transitions in crowd flow: first from laminar to stop-and-go flows, then to "turbulent" flows, which caused severe trampling accidents. The study reveals that high-density flows can become unstable, leading to sudden pressure releases similar to earthquakes. These transitions are not well understood, but the research identifies key factors such as local density, velocity variance, and "pressure" as critical indicators of crowd instability. The "pressure" is defined as the product of local pedestrian density and velocity variance, and it helps predict critical crowd conditions. The study also shows that in extreme densities, pedestrian motion remains finite, and the crowd can develop irregular flows, leading to shockwaves and safety hazards. The findings have important implications for organizing safer mass events, as they allow for early warning systems and adjustments in crowd management. The insights from this study contributed to the successful organization of a safe Hajj in 1427H, with changes such as improved stoning capacity, better crowd flow management, and the removal of bottlenecks. The research highlights the need for further simulation models that can accurately predict crowd dynamics, especially in high-density situations. The study also emphasizes the importance of understanding the mechanisms behind crowd panics and the role of local conditions in determining crowd behavior. The findings have broader implications for other mass gatherings, as similar dynamics can occur in various crowded environments. The study underscores the importance of real-time monitoring and adaptive crowd control strategies to prevent disasters.