The Mansfield Fire Department is investigating a fire that broke out Sunday morning on South Main Street that sent two Mansfield Fire fighters to the hospital. The blaze took place at 300 South Main Street around 9:20 am and spread into the vacant structure next door. One person was taken to the hospital and the exact cause is not known at this time. The Mansfield Fire fighters were sent to the hospital for treatment and evaluation. Both structures had pretty heavy damage done by the fire.