A downed host can't alert, it's down so it can't trap. They run an embedded, cut-down version of XP as far as I'm aware so are useless at the best of times. I doubt they're even monitored remotely (as all monitoring is done, it's what SNMP is for), and I'm not sure they care anyway.
Can I rant about HFN? I'm going to anyway.
The entrance/exit is way too small, in an emergency nobody is getting out in a hurry, you're better off running toward a platform in the event of an emergency at rush hour, unless the emergency is at a platform. All the recent work made the tunnel narrower so that makes the exit problem worse, or at least the queue longer. The ticket barriers, when in operation, force people to back up the stairs when a commuter train arrives, and the tickets bought from HFN sometimes don't work on the barriers, so I have to interrupt a staff conversation to get through. The staff are more interested in talking amongst themselves than being proactive when it isn't busy.
In almost a decade I've only ever seen one person selling tickets at the window, and twice I've missed a train because the lone person at the window has just upped and left as I got to the front, because he had to go to the toilet. That's fine of course, we all need to do that, but please John (I'm sure we all know John), don't shout at me when I ask why you walked off while I'm mid-sentence asking for a monthly season ticket, which the machines can't provide. Just explain you need a to visit the gents *before* you go. I imagine he hates his job as much as I hate using that so-called service so I can't really blame him for not caring, his employers care even less. Despite my understanding of his predicament, it's not good enough.
Then there's the fact that most passengers tend to wait until they're walking down the stairs on their way home after work to check their phones for whatever facebook updates they deem so important, rather than doing so on the train, so you're stuck behind a bunch of dawdlers when all you want to do is get home. If you (not you Ewoowar, I mean "you" in the plural) do that, please don't do that, you're holding everyone up behind you and you don't even know it.