A BUILDING, which was still under construction in Ortigas Center in Pasig City, was razed on Monday afternoon. Senior Supt. Samuel Tadeo of the Bureau of Fire Protection said initial investigation revealed the fire started at 1:38 p.m. at the basement of Avant Garde building. The fire has reached fourth alarm. Firefighters had difficulty entering the building because of the thick smoke coming from the basement, which was used as a stock room. Explosions were also heard from the basement, which firefighters said were caused by cans of paints, LPG tanks, and acetylene tanks.