Why do I keep dying in 'Hangar 18 1/2'?

I'm on the Hangar 18 1/2 mission in Saints Row 3 and in the final part, when I have to destroy the generator (after protecting Kwilanna), instead of the generator exploding, and me being temporarily stunned on the ground with shock (as I've seen in YouTube videos), the generator explodes, but I die almost instantly and hence fail the mission.

Is there a way that I can avoid this?

Thanks