Tunguska Mystery Blast Solved?

mfarah writes: "This BBC article informs that an Italian scientist team has determined that the 1908 blast in Tunguska was in fact caused by a low density asteroid - that's why no crater was ever found. The article mentions that had the asteroid fallen into a populated area, instead of remote Siberia, hundreds of thousands of casualties would have been the result. Fortunately this news comes well after the "meteorite blast" fad has faded from Hollywood..."