No fire, and in the pictures I've seen, no wet spot on the ground around the airplane, so I'd guess more likely no fuel.
As I recall from 25 years ago, the Shrike fuel gauges were pretty bad. Swede ran out of gas in Shrike, and had to land in a field. It was not dissimilar from this, actually-- he had to run down to Eugene or somewhere close to pick someone up, the gauges showed enough fuel (but not a lot extra, to be fair), and he ran out on the way home. At least that's how I remember him telling it.
