BAY RIDGE - Two children were killed Thursday in a fire at a Bay Ridge home.The fire started around 5:30 a.m. at 514 73rd Street and spread to a connecting home. Fire officials say the victims were 2 and 4 years old. Their mother, aunt and two teenagers were taken to the hospital with minor injuries. Tenants in both homes were evacuated due to the fire.Eight firefighters were also taken to the hospital with injuries related to the blaze. The fire was brought under control around 7 a.m.