(NOTE: The first two photos are from Copper Canyon Fire & Medical Authority and the remainder except as noted are by Vyto Starinskas of Verde Valley News.)
Here's what happened. The first truck somehow went off the Soutbound right lane into the bar ditch while the trailer kept going south and flipped over blocking both southbound lanes. Meanwhile, the semi tractor burst into flames. Luckily, the driver was able to bail out before he was injured.
Traffic began to back up farther and farther north in the southbound lanes until it finally began to back up into a perennial danger zone just downhill from the truck runaway ramp. The truck runaway ramp was built after a runaway truck killed a family of 8 people stopped in a line of traffic just north of the Sedona exit back in the 1980's.
A speeding semi came around the curve by the runaway ramp. And, naturally, the semi did what speeding semis are wont to do in such a case. It plowed into a bunch of stopped cars, crashing them willy nilly hither and yon.
According to the Verde Independent, "“This accident appeared to be caused by a tractor trailer that was unable to slow down in time and struck several vehicles that were stopped due to the first accident,” said Fire Chief Keller. A total of ten patients were assessed, and seven were transported with five ambulances from CCFMA, VVFD, SFD, Verde Valley Ambulance, and Pinewood Fire District. A total of four patients were transported to Flagstaff with more serious injuries, while the other three went to Verde Valley Medical Center, according to the release. It was reported that the resulting traffic jam extended up the grade nearly to the Stoneman Lake Road exit before the Department of Public Safety and Arizona Department of Transportation were able to open one lane of traffic for southbound travel."
The above photo was posted by the ADOT Twitter at 2:335 PM, October 30, 2017
.Here are two videos of both crash scenes by Vyto Starinskas of Verde Valley News