Lexington County fire officials say a fire that destroyed an apartment building Friday was caused by "improperly discarded smoking material" and caused almost $1 million in damage.The blaze broke out around 7:30 p.m. Friday in one building at Waterway Apartments on Northpoint Drive in the town of Lexington. A total of 16 units were completely destroyed, with two adjacent buildings suffering some external damage. Damage estimates to the buildings are $950,000, the Fire Service said Monday. The total does not include contents lost in each apartment unit. The Fire Service said improperly discarded smoking material was left on a first floor back porch area. According to a news release issued Monday, "Flammable landscaping materials were located along the exterior slab porch and exterior wall. Once the fire began it quickly progressed up the exterior wall and into an attic area. The attic area was made of lightweight truss construction and contained no fire walls.