] Top investigators of the Columbia space shuttle disaster
] are analyzing a startling photograph -- snapped by an
] amateur astronomer from a San Francisco hillside -- that
] appears to show a purplish electrical bolt striking the
] craft as it streaked across the California sky.

I personally think it's just a camera problem.

S.F. man's astounding photo / Mysterious purple streak is shown hitting Columbia 7 minutes before it disintegrated