CHESTER COUNTY, Pa. (CBS) -- A mystery in Chester County remains unsolved after four people reported feeling sick after opening a piece of mail. Police in Caln Township and hazmat crews responded to the unit block of Nancy Lane Tuesday night.
Officials say the four people felt dizzy and light-headed after opening an envelope.
They were checked on at the scene as the neighborhood was secured and refused treatment.
The envelope was tested, but police said Wednesday that no hazardous substances were identified.
"I would like to know what was going on. I mean inquiring minds want to know," neighbor Ray Mynatt said. "I mean this is where I live and I'm concerned."
Police say they have not received any other reports of people feeling sick.
The case is still under investigation.
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