HOUSTON -- The North Loop and the Katy Freeway inbound were both brought to a halt early Thursday after separate incidents involving big rigs.

Around 3:30 a.m. a big rig trailer loaded with cardboard went up in flames in the eastbound lanes of the North Loop near N. Main. All lanes were shut down for hours. Crews finally cleared the scene later that morning.

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Raw video: Trailer loaded with cardboard goes up in flames on North Loop

Officials at the scene said the truck was carrying more than 10 tons of cardboard when it caught fire. It appeared the driver of the rig disconnected his cab from the cargo trailer before it caught fire.

Photos: Trailer loaded with cardboard goes up in flames on North Loop

“I started seeing drops of fire fall to the ground and smoke coming off. When I see that I immediately dropped the trailer. As far as I know it engulfed in flames,” Joseph Shepard, driver, said.

The other problem firefighters were tackling was that the trailer axles have melted away, so they’re trying to figure out how exactly to remove the trailer.

The alternate route for the North Freeway fire was the Katy Freeway until the Katy Freeway, too, had an issue of its own. Around 6 a.m. a flat bed big rig's cargo box hit the Houston Avenue bridge. The cargo box fell off the rig and onto the shoulder, blocking a mainlane as well. It has since cleared.