Which acute threat arose during tunnel warfare by Roman legionary sappers when undermining enemy fortifications?

💡 Explanation

Suffocation was a significant risk because subterranean gas pockets, particularly methane or carbon dioxide from decomposing organic matter, would displace breathable air via diffusion. This deprivation of oxygen therefore caused asphyxiation rather than structural collapse or combustion hazards.

• For Viking longships navigating near icebergs, which risk increased due to sea spray freezing on the sail?
• Which risk increased for 18th-century wooden ships continually sailing tropical waters?
• Which risk increased in ancient Sumerian irrigation canals when the Euphrates River experienced prolonged drought?
• Which unintended consequence occurred because of the delayed ignition impacting effectiveness of the Congreve rockets during Napoleonic Wars?
• Which outcome regarding sail performance arises from increased frictional drag on early Viking longship sails?
• Which risk increases when early medieval fortifications employ weaker motte-and-bailey wall construction?