Derailed passenger cars involved in the <a href="https://en.wikipedia.org/wiki/2015_Philadelphia_train_derailment" class="extiw" title="w:2015 Philadelphia train derailment">2015 Philadelphia train derailment</a>. (Original caption: "Two passenger cars on their side and the remains of a damaged passenger car")
National Transportation Safety Board
2015-05
<a rel="nofollow" class="external text" href="https://www.ntsb.gov/investigations/AccidentReports/Pages/DCA15MR010_Preliminary.aspx">Preliminary Report: Railroad ​DCA15MR010</a> (released June 2, 2015)