Complex sentence: Demolition work began in July 1931 and the structure was finished off with explosives on December 5,1931; however, water seepage into the site from the nearby Moskva River soon turned the area into a giant stagnant pond, delaying construction.
Split into simpler sentences: Demolition work began in July 1931 and the structure was finished off with explosives on December 5,1931. However, water seepage into the site from the nearby Moskva River soon turned the area into a giant stagnant pond, delaying construction.