Hay and chicken parts "flew all over the highway" after a strap on a tarp came loose from the trailer as it headed down the hill on the southbound highway in Ramsey shortly before 6 p.m., one witness said.
The driver "braked to stop near the iHop and it all spilled over the top onto the trailer connections," he added.
"It's the worst smell you ever smelled in your life," another witness said. "I was gagging."
Responding police officers summoned the state Department of Transportation.
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