JACKSONVILLE, Fla. – Carbon monoxide readings were well over lethal levels Friday in a condominium where an 88-year-old woman was found dead, according to a Jacksonville Sheriff's Office report.
Firefighters forced their way into Jean Mertens' Cottages of Greenland home in Mandarin after a welfare check call was made to police.
The firefighters found Mertens dead and carbon monoxide levels in the home at 499 parts per million. A level of 400 ppm can be lethal after three hours.
Police said Friday that Mertens had a left a car running in the attached garage, accidentally filling her home with the deadly exhaust fumes, which also seeped into neighbors' condos.
When officers got to the home after a friend called asking for a welfare check on Mertens, they were met by people feeling sick and complaining of a strange odor.
After Mertens was found dead and firefighters saw the carbon monoxide readings, all of the adjoining homes were evacuated to get people away from the fumes.
At least three neighbors reported feeling sick for around 24 hours. Police said those men are expected to be OK.
A relative of Mertens said by phone Monday that her loved ones are a bit overwhelmed right now and are working on funeral plans.
Keyless ignition concerns
Many newer model cars are equipped with push button ignitions that start and stop the car and can turn themselves off if they have been running with no movement for more than a few minutes.
An investigator with Jacksonville Fire and Rescue told News4Jax the car involved was not a keyless ignition, but experts have said that those cars are the most likely to be left on.
RELATED: How keyless ignition cars can claim lives
News4Jax held an experiment in 2016 to see how dangerous exhaust fumes can be.
We put an SUV with a push-button ignition inside a garage with a plexiglass door and watched with firefighters as the carbon monoxide levels climbed.
After 30 minutes of the experiment, our experts said the levels in the garage could be lethal, and the levels climbed so high that we stopped the experiment an hour after we started.
Firefighters had to use an air pack and oxygen tank just to go inside the garage and shut the SUV off.
First responders said they want to make sure everyone has a working carbon monoxide alarm in their home to alert them to toxic gas leaks.