On FOX the stupid congressman or councilman or whatever he is said the fires began because people didn't evacuate. He backed off when questioned by reporter ... said maybe because homes were close together. Duh!
In better days ...
Looking back at some of the raw video feed from the NBC site you linked it does look like a gas line fire - at least at the very beginning of the footage before it really started spreading. Like a lighter with the flame on high down near the base of a building.
Saw some remarkable footage of the 14th St. Substation explosion that plunged Manhattan into darkness.
This is only going to get worse as day breaks and reports start coming in more rapidly. So sad...