AUBURN (CBS13) — A deadly hazardous materials incident closed down the Foresthill Bridge near Auburn for several hours Thursday afternoon.

The bridge began reopening shortly after 5 p.m. A chemical was found inside a vehicle that was parked near the bridge, the Placer County Sheriff’s Office said.

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Deputies found a warning letter on the car but are not disclosing the details if it. Hazmat crews later found two chemicals mixed together to make hydrogen sulfide in the car.

Additionally, Placer County firefighters broke the window to find a person dead inside.

“In smaller doses, that gas can be a throat irritant, coughing, nausea, vomiting, headaches, but at high concentrations and since the vehicle was closed, it can cause death,” said Battalion Chief Matthew Rea of the Placer County Fire Department.

So how do crews make a hazmat situation like this safe for them to contain?

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“We basically used other chemicals to make it into a solid to make into a neutral base so it is not a hazardous,” Rea said. “Once we have one step completed, we decontaminate the firefighters, almost like a blow up kids pool that you stand in and you scrub and clean so everything takes a long time.”

Both directions on the bridge were closed.

The Placer County Sheriff’s Office confirmed to CBS13 Thursday afternoon that a deputy initially located and approached the vehicle and found the note on it. That deputy reportedly had a reaction to what was inside the vehicle.

The deputy was taken to the hospital. The sheriff’s office said the deputy has been treated and was alert and talking.

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Further details on the person found dead were not released. However, authorities said this is not a criminal investigation.