Three Critically Injured in Crash With Washington DC Fire Apparatus            Courtesy of FireSceneAudio.com    WUSA9.com Video Friday, March 12, 2010  - Traffic in the District was snarled for hours Friday morning as police investigated a traffic collision involving a D.C. Fire truck that seriously injured three people. Commuters heading into the District Friday were met with heavy delays. Officials say most of the back-up was due to a collision at the intersection of 14th and Constitution Avenue. According to D.C. Fire and EMS Spokesman Peter Piringer, three people were taken to the hospital with serious injuries. No firefighters were injured in the crash. Piringer says the fire truck was responding to a call at a library at George Washington University where a small fire broke out. En route, Piringer says, the truck hit one car at the intersection and that car struck another vehicle at about 7:30 a.m. He says the fire truck had red lights and sirens on as it headed westbound on Constitution. He says it is unclear at this time what direction the two cars were headed. The busy downtown intersection remained closed for hours as police investigated the scene, and commuters felt the ripple effect. At this time, the crash has been cleared and all lanes are reopened. The fire at the library ended up being a small fire in the heating and air conditioning system. Piringer says it was quickly contained.