A chimney fire causes heavy damage to a home on Janesville’s east side. Firefighters were called to the 3700 block of Bryn-Mawr Drive about 6:30 p.m. Thursday. Flames were showing through the roof when firefighters arrived. The preliminary investigation indicates the blaze likely began in a gas fireplace. Damage to the structure is estimated around $80 thousand with $30 thousand damage to the contents.