The group of armed extremists didn't just rashly decide to turn this cave into their second trap location and install 50 tons of explosives; they had someone analyze the geological structure of the place. In the eyes of an expert, the cave was incredibly sturdy, unlikely to collapse, which is why they set up the second ambush here.
Indeed, the choice by the armed extremists proved to be correct. Despite the severe explosion of 50-ton high explosives in the outside passage, even causing the entrance to collapse, the explosion and collapse were contained at the entrance and didn't reach the inside of the cave.
The huge explosion in the passage generated a large amount of gunpowder, smoke, and rock dust, which backfilled into the cave under great pressure, like a hurricane sweeping through swiftly, engulfing everyone in the cave in dust in merely a moment.
