The victim was driving southbound on 146 when a large bolt belonging to a truck or trailer smashed through his windshield.
The bolt struck the man in the neck. He died as a result of his injuries.
PHOTOS: Man killed in freak accident on Hwy 146
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Investigators say the bolt is a retaining pin for containers attached to flatbed trailers.
The vehicle in question would have been traveling northbound on Highway 146 when it lost the bolt, police say.
A $5,000 reward is being offered for information that leads to her arrest.
If you have information about the driver, you can make an anonymous tip to Crime Stoppers by calling 713-222-TIPS or by submitting your tip online at www.crime-stoppers.org.
ORIGINAL REPORT: Flying bolt killed driver on Hwy 146, police say