Firefighters rescued several tenants from a Prospect Heights apartment fire this morning after flames ripped through the six-story structure. Investigators say the fire started shortly after 8 a.m. at 1154 Pacific St. Originating from a second-floor residence, the blaze spread to the fire escape and blocked residents fleeing from the upper floors. One woman told fire officials that she believes an electrical fire sparked the inferno. Firefighters stayed at the scene after the flames were put out to ensure that no embers remained in the apartment. No injuries were reported.