A big rig hauling Amazon products overturned on the 210 freeway early Monday morning, causing a massive traffic jam that extended all the way east to Rancho Cucamonga.

Around 4:19 a.m., the truck apparently veered to the right while traveling westbound on the 210 through Claremont, going up an embankment and causing it to overturn just a few feet east of the Towne Avenue overpass, Officer Tony Chen of the California Highway Patrol said.

Officers were on scene within two minutes, and blocked off all westbound lanes as they cleaned up the accident. The driver of the truck was not injured, Officer Chen said.

The accident caused a traffic nightmare for motorists on their way to work this morning. Cars were bumper-to-bumper as far back as Rancho Cucamonga, and drivers looking for different routes also impacted Claremont side streets.

The cause of the crash is still under investigation, Officer Chen said. All lanes of the 210 were reopened just before 8 a.m.

—Matthew Bramlett

news@claremont-courier.com