A semi carrying a load of gravel tipped on the Broken Arrow Expressway in the eastbound lanes just before 3:30 Monday afternoon.
It happened near the Highway 169 junction.
KRMG listeners report traffic is backed up.
Traffic is being diverted to US-169.
Drivers are urged to avoid the area and locate an alternate route, especially through rush hour traffic.
The closure is expected to last several hours.
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