Jeep toad catches fire on interstate 15 in the Cajon pass

Read an article in todays Victorville daily press that stated that a Jeep being hauled by a motorhome thru the Cajon pass caught on fire and damaged the Jeep as well as the rear of the motorhome. Does anybody have more details as to what caused this to happen?
Thanks Don.

2005 Holiday Rambler Neptune
2006 Jeep Liberty 4x4 toad.