Investigators are still piecing together what happened in the deadly train derailment in Philadelphia, but Rachel Maddow blames Congress.

While noting that we're still awaiting the final results of the investigation, Maddow says infrastructure is so neglected in the United States that ultimately the details are nothing in comparison to what we already know about congressional leaders' failure.

"We are a great nation that has allowed the world-class national infrastructure that our grandparents built, and our parents handed down to us, to erode and suffer and starve to the point that it is decrepit and deadly," she said, "and this is a failure in governance. This is on Congress' head."

Before starting the lengthy segment, Maddow warned her viewers that she was emotional about the topic. She lost an NBC colleague in a rail crash that was also preventable.

Then, as is the usual Maddow way, she took viewers first through a history of rail crashes caused by human error and outlined how available technology could eliminate the possibility of those errors causing deaths.

Watch the video below: