FPV shot: The camera flies through a flooded subway system as tunnels collapse behind it. Water rushes through the corridors with unstoppable force, smashing lights, signs, and concrete pillars. The camera dives beneath the surface, dodging floating debris, electrical sparks, and spinning metal panels. A train derails ahead, creating a violent underwater shockwave. Foam, bubbles, and broken fragments rise together, sculpting the word "ESCAPE" before the tunnel ceiling collapses and the flood consumes everything. Claustrophobic action, water destruction, high tension.