Re: "the (suicidal?) bravery (stupidity?) of our colleague"
Im pretty sure fire is generally thought to double in intensity every minute. Therefore it can very rapidly get out of control.
Many years ago I lived on a hill street where the houses had enough space underneath to stand up. Many of the places, including my uphill neighbour's, had a full-sized doorway leading to an area set up with shelving much like a garden shed or small workshop. These neighbours had all sorts of stuff stored there from years of living in the same place.
3 generations lived there - the grandmother, the parents and the kids.
I got home from work one day to see their eldest boy (then about 8 or 9) running out from under the place, and some smoke coming out as well. I walked closer to the fence and saw a small amount of flame - not even the size of a decent wastebin fire (I mean deskside bin with a half a dozen balled bits of A4). I raced inside, yelled to my GF to call the fire brigade, and went outside for the garden hose.
She was outside a moment later, fire engines on the way (but not sure why). She saw what was going on, gave them more details, then rushed into the neighbour's house to alert them (kid was nowhere to be seen). The father came out while the mother got the rest of them outside. The father grabbed their hose and helped. Thankfully close to the fire station so we had extra help inside of 5 minutes - we were barely able to keep the fire under control let alone stop it.
It was clear that had I gotten home even a couple of minutes later, both our houses could've been lost. But more - the grandmother was bed-ridden and probably wouldn't have made it out in time if it hadn't been for my initial water slowing the spread of the fire (had I thrown a rock through their window and started yelling, bringing the father out earlier, we probably could've stopped it with both our hoses). If I'd gone inside their house - the fire was under the old girl's bedroom and with the way things were stacked, good chance we wouldn't have got her out. It would normally take me about 10 minutes to get home from work back then - any small change to the length of time of the trip shorter or longer (eg if I've been inside my house before the boy ran out from under his)
They lost a lot of family memorabilia, and the framing underneath needed some repair work, but the house still stands (and while it's still 3 generations, 2 of them have moved up a notch...) There is still signs of the charring to the top of the door frame.
I don't consider this anything even remotely heroic as I could've backed away at any time and don't think I was in any fashion in any risk.
I've been in two house fires (counting the above). Fire spreads amazingly fast when it wants to[1]. 30 seconds is a hell of a long time when you have a fire kicking off. Slow it down (and get your extinguisher as close to the source/seat of the fire as you can), but get someone on to the emergency services quickly. If you can, get a sprinkler or other suppression system installed but don't expect them to do much more than slow things down. If you can't slow it down, get everyone out as quickly as you can. In many cases you've only got 10 seconds from when it starts to stop it with any ease. 30 seconds and it's probably beyond a garden hose, 1 minute and anyone inside is toast.
As to the kid? I didn't see him for a few days, but middle of the next week he brought over a very nice meal he'd spent much of the day making, and was both very apologetic and very thankful. He'd been playing with candles and dropped one on some empty cardboard boxes... I understand it was another week before he was able to sit down...
[1] As others have said - why is my damned BBQ so hard to start? Why do I need 3 goes, even with the best kindling and fire starters, to get the house warming up? Fire is alive I tell you, and has a rather sadistic/vindictive mind of its own!