Delta computer crash. Again

This morning's Wall St Journal had a few words from Delta's chairman.  He says an equipment failure on Delta's site both knocked out the system AND started a small fire.  A fire?  Where are the Halon fire extinguishers that any decent computer room has???   We actually had them go off once at my old place.  It was a false alarm, and it's a good thing that Halon just puts out fires and doesn't wreck electrical equipment like water will do.  But the question for Delta is, why didn't your Halon extinguishers work?