(Coon Rapids, MN)  --  Trouble seems to be coming in "threes" in the city of Coon Rapids.  This week, the northern Twin Cities suburb has seen a Northstar rail accident which killed a train worker and the sexual assault of a six-year old girl where the suspect remains at large.  Now there are reports that, since last Friday, three different women in the city were robbed by the same armed man.  One of the women was assaulted during the theft.  Coon Rapids Police are offering a one-thousand dollar reward for information leading to an arrest in that case.