VIDEO: The State Fire Marshal is investigating after a fire at a construction site in Mukwonago. Crews were on the scene for hours. Around 3:30 a.m. on Thursday, May 4th, smoke could been seen for miles as flames engulfed an apartment building at Phantom Woods Road and Main Street in Mukwonago. "Fortunately, the water service was in place, so we were able to use the hydrants that were here," said Mukwonago Fire Chief Jeffrey Stien. The complex is under construction, so luckily it was not yet occupied.