Many factors caused the collapse which took place August 1, 2007 around 6:00pm with a number of fatalities. At the time of the I-35W Mississippi Bridge collapse construction workers were making additions to the 40 year old structure in hopes of separating the eastbound and westbound lanes. With the bridge being built in the 1960s there were many changes that needed to be made which put stress on the structure and girders over the course of time. With Tons of construction equipment and cars due to rush hour traffic, the bridge was pushed to the limit as the old weak girders wore down causing the bridge to collapse in three sections. Being built in 1967, many design flaws were made that should have been changed over time to improve the strength
