Four people ran for their lives when fire broke out overnight at an Everett duplex, officials said. Crews responded to the scene, in the 800 block of Locust Street, at around 2 a.m. Friday after receiving multiple 911 calls about smoke and flames at the residence. One half of the duplex was fully engulfed in flames when first responders arrived. Firefighters immediately went on the offensive and prevented the blaze from spreading to the second duplex unit. Four adult residents of the duplex were able to escape. No injuries were reported. The cause of the fire is under investigation. No damage estimate was immediately available.