Engineers Deaths caused by their own fail safe device.

That is a good shout because there aint nothing else on the recordings, and would also explain the way he dies.But what about the piled up bodies? They got holes all in them. Maybe they had to get in that room, AND THEN de-contaminate the pyramid... the last one not making it. And the bodies were being prepared by whatever goo'd creature was after them.

I think some were infected with the black goo when they started to run. As they were running a decontamination agent was released into the environment. The decontamination agent was design to contain/destroy what ever they were working on. I think where the piled up bodies are, at the door. They were trying to breach the door and thats where they died.