The complex from chapter “Blast Pit” is supposed to be sealed off and abandoned, just like parts of Aperture Science from Portal 2 chapters “The Fall” and “The Reunion”. So why are there so many scientists in there?
They probably got forced deeper into the facility once they started to realize the military was there to execute people.
^this.
Or they were already there. You never know, considering the idea behind BMRF.
Well, let’s see: The corridors and tunnels Gordon crosses to reach the rocket test chamber are flooded with radioactive waste and crawling with zombies, houndeyes, headcrabs, and bullsquids, meaning it would be extremely dangerous for anyone without a hazard suit and weapons to navigate. Also, correct me if I’m wrong, but I think the only ways in or out of that area are through the rocket test chamber (one the way you enter the area in the game, through the radioactive waste, the other the way you exit, through the rocket exhaust tunnel). So, unless the radioactive waste leak and the teleportation of the various Xenians, including the Tentacles, all happened later on after the military arrived and the scientists found out they were hostile, but before Gordon could reach them, then it’s most probable that they were already there. However, there is a barrier made of boxes and boards at the beginning of the chapter, suggesting that maybe someone built it before retreating further back to the rocket test chamber…or it could have been built to keep the Xenians inside. The fact that the fan for the test chamber was boarded up and the fuel and power were turned off suggests that maybe it was abandoned and no one was there before the Cascade after all. The fact that everything still worked and there was still fuel left might indicate they were still using it, or planning to use it again in the future. Perhaps the scientists were there to start more tests that day.
TL;DR - Seems to be evidence either way. Two most probable scenarios: One, the scientists hid there from military, waste leaks out and Tentacles teleport in, trapping them; or two, the scientists were already in there and were trapped inside at the beginning of the Cascade.
EDIT: Think I misunderstood OP’s question. Edited my response to be a bit more relevant. Also I’ve spent too much time thinking about this, the end result is there’s scientists trapped in there and Valve probably didn’t put any thought or significance to why they were there except to hide.
The pit is where they hang out and smoke the dopepotweed because there are no cameras in there
^that
I think they were already there. I mean, they had running equipment in there and stuff.
They probably realized that, so long as there’s a mile-deep missile silo right next to the storage facility and rocket launch pad, they may as well repurpose it into storage and rocket testing. Like how they were using converted industrial areas as pools to store leeches and ichthyosaurs in Apprehension.
I bet the ridiculously oversized silo was where they kept the giant rocket they used to banish Gamera to Mars.
I just watched that movie last week. MST3K version of course. So cheesy.