I noticed this recently on Google Earth located on the southwest corner of KLAX in Playa Del Ray, CA.
Upon examination, I'm guessing the facility is used by firefighting crews for practice putting out jet fuel fires on an aircraft on the ground. I'd also venture a guess that the smaller fuselages to the right are probably used by the LAPD SWAT team, federal sky marshals or other LE organizations for doing anti-hijacking and other anti-terrorism training.
But what's with all the taxiway paint markings around the red fire aircraft? Do airport paint crews go out there to test their equipment?