If you would like to see what happens during a toxic leak/spill, check out this report ...
http://www.interfire.org/res_file/pdf/Tr-052.pdf...of what happened in Henderson, NV (near Las Vegas) on May 6, 1991. I'm sure you will hope that your community has more intelligent people where it matters than did/does Henderson & Las Vegas.
This was a spill of 70 TONS of chlorine. When it started, the employees "thought they could handle it", so they didn't notify anyone. A woman passing on the elevated freeway called 911 from her car to report an acrid odor and a visibly green glowing cloud.
The 911 dispatchers blew her off, and the recording after she hung up showed how they called her a dumb [censored] who doesn't know squat. They didn't send anyone to check it, or notify anyone else that there might be a problem.
About 20-30 minutes later someone else called, indicating there might be a problem, but no one knew where to look because the site with the problem still hadn't called in.
When the fire dept/police figured out what was going on, they started looking around, and finally found the employees who "thought they could handle it" in need of immediate medical attention.
They started evacuating people in the area about 3:30 a.m., and several hundred had to be taken to the local hospitals, all of which were now on full alert.
There were fire and police personnel from many stations in both Henderson and Vegas, but NATURALLY, most of them couldn't communicate with each other because of use of different radio frequencies.
And, since it makes perfect sense to place chlorine factories (& other toxic liquids & gases) near places like hospitals and retirement homes, they had to evacuate everything but the hospital, which they decided not to due, as they said (hoped) that if they closed it up and had the a/c only recirculate interior air, it would be okay.
BTW, this is the same area that had the rocket fuel factory (PEPCON) blow up in 1988 and flattened everything nearby, providing two explosions (3.0 & 3.5 on the Richter earthquake scale), and leaving a crater 15' deep and over 200'+ across. Only two people died here, one who called the fire dept. & the other was in a wheelchair and couldn't escape. Fortunately, they did have an evacuation system, and started it immediately. Due to the force of the explosion, there were hundreds of injuries. I heard that one brave man grabbed a female employee out of her wheelchair and ran with her over his shoulder to safety. Due to rapidly-accelerating conditions, I don't believe there was any warning to anyone outside the factory itself.
The video of the explosions from some hills just south of the site (which I just saw for the first time 2 yrs ago) were incredible. You could SEE the shock waves!
http://www.interfire.org/res_file/pdf/Tr-021.pdf (PEPCON explosion)
My point: if anything remotely like these take place near you, RUN LIKE HELL FOR THE CAR AND GET OUT, and don't hang around to protect your property. And it doesn't matter if you have a gas mask or not.
Sue