Authorities are looking to the wintry weather for causing an accident that killed a Tama County man early today.Icy roads may be to blame for the one-car rollover wreck in Tama County that injured the driver, 33-year-old Todd Seda of Clutier. A passenger was killed, 46-year-old Dean Jacobs, also of Clutier. Seda was treated at a Waterloo hospital and released.