It happened around 3:20pm on the Southwest Freeway at Chimney Rock, shutting down the roadway for hours, causing a traffic nightmare.
On his drive home to Galveston, Quenton Charlot witnessed something he never expected.
"Just looking over there, it was a catastrophe," he said. "Just from the drivers around me, you could see their faces. It was complete horror."
Houston police say the driver of a red SUV was driving erratically and collided with an 18-wheeler bearing the USPS logo. Both vehicles then caught fire.
"The front part of the truck was hanging over the freeway and it was on fire," Charlot said.
Traffic quickly built and rush hour snarled, as first responders arrived to help. The fire burned for 20 minutes.
"The first thing I wondered was, is anybody hurt? If they were hurt, how bad? I even said a prayer on the inside for all the people involved," Charlot said.
The driver of the 18-wheeler is in the hospital and is expected to recover. But the other driver, by witness accounts -- a woman -- didn't make it out alive.
"It just touched my heart because it makes you count your blessings. Don't take life for granted," Charlot said.
USPS says there was no mail in the 18-wheeler.
The cause of the crash is under investigation by HPD's Vehicular Crimes Division.
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