Arson in Arlington, VA (Crystal City)....or was it?

I took these pix on Friday...May 23rd. These buses were parked outside the Hilton Hotel in Crystal City (Arlington), VA. I talked to a policeman and he said they were discovered on fire at around 3am and they were still investigating whether it was an arson.

Did anyone ever here was it really arson?

I was told this tour buses were used by a high school band from MN.

I took these pix with my camera phone.