There are some images that are indelibly etched in our minds, and one of them is the fall of theI-35W bridge in downtown Minneapolis.

As the 10th anniversary of the horrific tragedy approaches, there will be many observances of the moment just after 6 p.m. on Aug. 1, 2007 when the eight-lane, steel truss arch bridge that carried traffic over the St. Anthony Falls on the Mississippi River went tumbling into the water below.

The incident left 13 people dead and 145 injured.

On Tuesday, the Hennepin County Sheriff's Office will hold a wreath laying ceremony for first responders to mark the anniversary of the collapse of Bridge No. 9340. They will meet at 1:45 p.m. at Bohemian Flats Park, 2100 West River Parkway, Minneapolis.

The National Transportation Safety Board cited a design flaw as the likely cause of the collapse.