NEWBURYPORT - In a county where 93 people have died of drug overdoses in the last two years alone, Newburyport is hardly immune to the growing horror of heroin addiction. On Thursday night, Mayor Mary Anne Clancy's Task Force on Underage Substance Abuse plans to issue parents with warnings of what to look for, and what to do if their child falls victim to opiates. The public forum, entitled, "Do you know what your children are doing tonight?" will be held from 7 p.m. to 9 p.m. in the Newburyport High School Auditorium. [continues 743 words]