Two workers died Thursday afternoon after they passed out inside a manhole in Aldan, Delaware County, according to reports.
Authorities were called to the scene at West Rively and South Sycamore avenues around 11:15 a.m., 6ABC reports.
Emergency crew members responded to the scene to remove the workers from the 30-foot-deep manhole.
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The two victims, who were not immediately identified, were unresponsive when pulled from the manhole around 12:15 p.m. and later pronounced dead.
Alden Police Chief Ken Coppola said the victims were in their early twenties and were conducting a dye test when they fell out of contact with two other co-workers on the other end of the street, according to CBS3.
Hazmat crews were sent to the scene to investigate. It's not yet known what caused the workers to fall unconscious in the manhole.