Firefighters rescued at least seven people after a blaze erupted on the top floor of a three-story residential building in West Oakland sending towering flames and heavy smoke into the dawn sky. Fire officials said at least one person was feared dead inside the building at Mead Avenue and Market Street that houses a drug rehabilitation center. Battalion Chief Eric Logan of the Oakland Fire Department said firefighters who entered the structure thought they saw a body on the third floor, but couldn’t reach the person before flames and heavy smoke caused them to pull out of the building. “When firefighters first went in, they saw what might have looked like a body on the third floor, but the flames were so intense they had to retreat,” Logan said. The fire broke out just before 6 a.m.