A former Onalaska man has been sentenced to 10 years in prison for the repeat sexual assault of a teenager. Prosecutors say Bruce Nelson was 37 years old when he convinced a 13-year-old girl he was just 19. W-K-B-T / T-V reports they had sex and the girl became pregnant. That was three years ago. La Crosse County Circuit Judge Elliott Levine denied a request for a sentence of probation. He said that would be inappropriate. Nelson has been ordered to have no contact with the victim or anyone under 18 years of age.