The Oklahoma Highway Patrol is looking for witnesses to a deadly crash on the Turner Turnpike just west of the Sapulpa exit Wednesday.
Troopers say the driver of a 2007 Chrysler Minivan, 77-year-old Arthur O'Connor of Bristow, struck a concrete riser which had fallen from a 2006 Freightliner pulling a flatbed trailer.
The crash happened in the eastbound lanes of I-44 at 12:23 p.m.
The OHP says the semi's driver, Paul Hutchinson, 46, of Pawnee pulled over and stopped on the highway's shoulder.
The trooper's report states O'Connor swerved to avoid the concrete, causing him to lose control and sliding into the semi's trailer. O'Connor was taken to a Sapulpa hospital where he later died.
They are wanting to talk with any drivers who witnessed the falling concrete and the resulting crash.
Call 1-866-OHP-TIPS(646-8477) if you have any information.