THE ACFT COLLIDED WITH A RADIO ANTENNA SUPPORT CABLE AT APRX 171 FT AGL DURING LOW ALTITUDE MANEUVERING IN SNOW SHOWERS.ONE WITNESS STATED THAT THE HEAVIEST SNOW SHOWERS WERE IN THE VICINITY OF THE ACCIDENT SITE. A POLICEMAN SAW THE ACFT OVER A FIELD NEAR THE KDWB RADIO ANTENNA. DURING THE WX BRIEFING THAT THE PLT RECEIVED 11 HOURS PRIOR TO THE ACCIDENT THE WX WAS FORECAST TO CONSIST OF LOWERING CEILINGS, TURBULENCE AND ICING FOR THE PLANNED AFTERNOON RETURN FLT. ACCORDING TO RELATIVES WHO SAW THE FLT DEPART PRAIRIE DUE CHIEN AT ABOUT 1600 HRS CDT, IT WAS RAINING. LATER IN THE FLT THE PLT ANNOUNCED OVER THE RADIO THAT HE WAS DISORIENTED AND WHEN ASST WAS OFFERED HE STATED, 'I SURE COULD USE IT, YES.' HE WAS GIVEN VECTORS BY APPROACH CONTROL AND TOLD TO STEER 260 DEGREES. WHEN ASKED HIS ALT HE DID NOT RESPOND. THELAST RADAR CONTACT WAS IN THE VICINITY OF THE ACCIDENT SITE.