Victim worked in IRS office in building where crash happened , WAAY says . Both men died from blunt force injuries , medical examiner 's office says . Authorities : Andrew Joseph Stack crash his single - engine aircraft into seven - story building . ` He hid that very well , '' said Billy Eli , in whose band Stack played bass until a few years ago . He set his home on fire before his death , authorities say .
Victim worked in IRS office in building where crash happened , WAAY says . Both men died from blunt force injuries , medical examiner 's office says . Authorities : Andrew Joseph Stack crash his single - engine aircraft into seven - story building . He set his home on fire before his death , authorities say .