Idaho State Police believe a commercial truck driver’s inattention was responsible for a seven-vehicle, four-fatality crash on Interstate 84 in Boise last month, according to an initial report of the crash released Thursday afternoon.

The massive crash — which took place at about 11:30 p.m. June 16 near the Cloverdale overpass on the interstate — resulted in the deaths of three U.S. airmen from Mountain Home Air Force Base — Senior Airman Carlos Johnson, Senior Airman Lawrence Manlapit III, and Senior Airman Karlie Westall. Illya D. Tsar, a truck driver from New York, also died in the ensuing fire, which scorched the Cloverdale overpass.

That stretch of highway that night was clear and dry, although it was dark and devoid of streetlights, according to the report. Troopers believe Tsar was not paying attention to the traffic ahead of him as vehicles slowed for road construction, although they do not know why or what might have distracted him. According to the report, troopers found no evidence drugs or alcohol played any role in the crash.

Tsar, who drove for the Kurjex Freight Transport Corporation, was hauling “hazardous materials,” although the report does not specify what those materials were. He was driving east, behind Johnson, who drove a 2008 Jeep Wrangler, with Manlapit and Westall inside. As Johnson slowed for traffic, Tsar did not, and he struck the Jeep from behind, according to ISP's report. The semitrailer and the Jeep kept moving after the crash, and initiated a domino effect when they rear-ended another semitrailer driven by Roman Zhuk.

That semitrailer then struck a 2006 Ford Fusion, driven by Toina Jorgensen; Jorgensen’s vehicle then crashed into a 2014 Ford F-150 driven by Gerald Shumway. Jorgensen’s 2006 Ford Fusion then sideswiped a 2015 Ford Escape with Fernando Nitu at the wheel. A seventh vehicle — a 2010 Ford Focus driven by Grace McNeil — was damaged by debris from the crash. The initial crash report does not include estimated speeds for any of the vehicles involved.

After the crash, some of the vehicles caught fire, and that fire killed Tsar, as well as Johnson, Manlapit and Westall, according to reports from the Ada County Coroner’s office.

The fire also seared the Cloverdale overpass, which has remained closed since. There is no cost estimate yet on the damage caused by the crash. 

The report remains almost silent on what construction in the area looked like that night. Work zone crews were conducting a joint seal project — a fairly routine occurrence for highway maintenance — and they narrowed four lanes of traffic to one. The Idaho State Police report notes the crash occurred in the “advance warning zone” before the work site — which is usually the 1 to 2 mile area where signs warn drivers to slow for an upcoming work zone. That night, according to the safety control plan crews followed, speed limits on I-84 dropped from 65 mph to 55 mph. The calculations involved in assembling the traffic controls for the work site assumed vehicles would travel at 55 mph, according to the safety control plan.

Some drivers who passed through the area in the 48 hours before the crash felt the work zone was unsafe and ill-marked, and a few of them called 911 to report it. One of them, Kevin Berringer, told the Idaho Press he and his wife passed through the work zone 24 hours before the crash occurred. In an audio clip of that call, obtained by the Idaho Press, Berringer tells the dispatcher crew should “get somebody out here to direct traffic,” because people were “flying down the left lane, ignoring the left lane ending.”

While the Idaho State Police report notes there were construction crews on site at the time of the crash, it also notes there were no law enforcement present to direct traffic. It does not appear to be standard practice in Idaho to have law enforcement officials direct traffic at work zones, according to Tim Marsano, spokesman for the Idaho State Police, and Jake Melder, spokesman for the Idaho Transportation Department.

Marsano confirmed the crash is still under investigation, and the final report may not come for a long time. Melder did not comment on the crash report by Wednesday evening.

Tommy Simmons is the Ada County public safety reporter for the Idaho Press. Follow him on Twitter @tsimmonsipt