A landmark building in downtown Des Moines caught fire and partially collapsed early this (Saturday) morning. KCCI-TV reports large numbers of firefighters and equipment responded to the three-alarm blaze at the former Younkers Department Store near 7^th and Walnut Streets. The blaze was reported at 12:50-a.m., and within minutes it was upgraded to a three-alarm fire.

Witnesses reported huge flames leaping from the upper floors of the building.  Video captured by one witness shows a huge part of one wall collapsing into the street. The upper floors of the structure were fully engulfed in flames when the first firefighting crews arrived. The flames spread quickly according to fire officials, because the building was under construction and many interior rooms were open.

As of 7-a.m., firefighters remained on the scene pouring water on what remains of the building. The inside of the building has collapsed. Buildings to the east and south of Younkers were damaged by falling debris and smoke, and nearby the Hub Tower was evacuated. It sustained significant damage due to the fire, including shattered windows and heat damage.

There is no word yet on what started the fire.