Downtown Louisville was shaken yesterday morning when an office building was demolished to make room for the new arena.The ten story building at Second and Main Streets was once owned by Humana. Mayor Jerry Abramson triggered the implosion. He says it marks the next phase in construction of the downtown arena.“It really is the end of the beginning. This building comes down, the financing gets in place maybe next week, as soon as next week," says Abramson. "The markets are settling down a bit.”Depending on the markets, a bond issue for the arena could be announced Wednesday, at the arena authority’s meeting.