Harvey firefighters were called to a building fire in the 500 block of Olive Ave. around 6:30 Monday afternoon. Upon arrival first units on the scene reported heavy smoke coming from the roof and gave a working fire and elevated to a second alarm. Family of the owners advised that no one was in the structure and that it had been vacant for several years. A short time later flames broke through the roof. Not long after that a portion of the roof began to collapse. For safety reasons all Firefighters were ordered out of the building at that point. Manpower was also requested from Terrytown and the city of Gretna. One hour after the initial call a third alarm was requested. Approximately one and a half hours after dispatch a fourth alarm was struck. It took approximately 30 Firefighters from across the Westbank including Westwego and Marrero three and a half hours to bring the blaze under control.