Place it at the turning point, right after a Metal Gear Alert Sound flags the danger and just before the fallout starts. Follow the aftermath with the Mortal Kombat Fatality sting to close the sequence, then move straight into your next clip without a second warning.
About this sound
A 2.4-second voice clip of the Red Queen calmly saying 'You're all going to die down here' in a flat, childlike computer voice. It feels chilling and ominous because the threat is delivered without emotion, like a system stating a fact. The line comes from the Red Queen, the artificial intelligence in the 2002 Resident Evil film.