AUSTIN, Texas – A software engineer furious with the Internal Revenue Service launched a suicide attack on the agency Thursday by crashing his small plane into an office building containing nearly 200 IRS employees, setting off a raging fire that sent workers fleeing for their lives. At least one person in the building was missing. The FBI tentatively identified the pilot as Joseph Stack. A federal law official said investigators were looking at a long anti-government screed and farewell note that he apparently posted on the Web earlier in the day as an explanation for what he was about to...