The 911 call came in at around 9 a.m.
Reports trickled in of a big rig crash on I-5, with 30 critically injured victims and a distinct odor of rotten eggs in the air.
Luckily, this time it was just a drill.
"The incident involved a tanker truck, loaded, carrying a type of pesticide we call an organophosphate," said Redding Deputy Fire Chief Gerry Gray.
"When the tanker truck actually crashed, it was involved with other vehicles, so those people had injuries from the initial crash. Plus, with traffic coming to a dead stop because of the incident, they were exposed to chemicals as well," added CAL FIRE PIO Kevin Colburn.
Once the incident is called in, emergency personnel are working against the clock.
They have one hour to administer antidotes to victims that have been exposed to the chemicals.
"It's absolutely critical that we get to these victims as soon as possible. The longer it takes for us to get to them, the less their chances are of full recovery or survival," Gray said.
Enter CHEMPACKS -- supplies of medication strategically placed all across the country.
They were first deployed in 2005.
"Its purpose is to provide antidotes to remedy a certain type of chemical, whether it's biological or a chemical attack from terrorism, or in this case an agricultural event," said Gray.
With all of the victims successfully treated, the HazMat team cleaned up the spill before it could reach nearby waterways and drains.
The American Red Cross was also on hand for the drill.
Volunteers were stationed at two nearby churches to practice sheltering evacuees and learning how to handle any contaminated victims.