Found hostages dead. Is it a bug?
First mission : Milwaukee Junction
In the first play-through, I completed the Typhoon objective first and found the hostages already dead when I arrived at the office where they were held. I figured that the gas bomb was activated when I was discovered by PF members. Also, I did not discover the overhead vent passage until much later.
Today, in my second play-through, I reload the first save file (and skip the lab attack tutorial). I intended to save the hostages but I keep finding them gassed to death. Even using the overhead passage, I saw them dead through the window. I reload the mission 3 times and they ended up dead each time.
At one time, while waiting in the clean room (as a cover for game level loading), I spot a subtitle text "Dispersal device activated. Have a nice day."
Giving up, I deleted the save file. I guess the only option left is to play from the start.
Did it happen to anyone else?
I know that if you wait too long at the HQ before boarding the chopper, the hostages can get killed.
When it says you should hurry up and talk to David Sarif, it means it :)
I had a friend that had that happen to him, needless to say David was pretty pissed :)
There are several ways of getting inside the hostage room and disarming the gas dispersal device before it goes off.
I've successfully done this in both playthroughs so far and especially the first time I played through the area I was anything but quick in getting to them. You're probably looking at a bug.
ETA Getting noticed by the terrorists does not trigger early release of the gas, as far as I'm aware. I was spotted more than once on my first playthrough (still getting used to the controls and not terribly good yet at checking angles of sight will do that to you) and there were still a couple minutes on the clock when I started hacking the gas bomb.
ETA 2 Spoiler warning, but if you want to be absolutely sure it's a bug and not just you, you can try following the walkthrough given here.
If the Hostages where alive when you started the mission and you just skip past them and do the other objectives, they die because swat was unable to disarm the bomb. I did this once just to see what happened.