A broken gas line on South Gay Street between East Gambier and East Vine streets forced the evacuation of an apartment building at 105 S. Gay St. and the offices of the Mount Vernon News this morning. The break was caused by work on the Gay Street Improvement Project. According to Paul Cline, project manager “The line wasn’t marked and it was supposed to be deeper. Workers from Columbia Gas tapped off the line at approximately 10:30.