There are no reports of injuries but the fire that swept through this apartment block under construction in the U.S. took a lot of fighting.<br/> <br />The blaze burned for several hours in the Mission Bay area of San Francisco despite the efforts of about 150 fire-fighters.<br/> <br />Officials said the blaze was more difficult to tackle because fire suppression systems had not yet been fitted inside the 360-apartment structure.<br/> <br />The property's developers said the cause of the fire was not immediately known.
