‘Very unusual’: Experts say carbon monoxide deaths in vehicles outside are rare

Fatalities from inhaling carbon monoxide in cars parked outside are relatively rare, experts say, as authorities continue to investigate the deaths of two teenagers in Hoffman Estates earlier this month.

Yeferson A. Flores Ramos, 17, of Hoffman Estates, and Litzy Flores, 16, of Carpentersville, were found unresponsive March 2 in a vehicle that was parked outside a home.

A preliminary autopsy indicated the two Conant High School students died of accidental carbon monoxide poisoning. The gas is colorless and odorless.

Firefighters are familiar with carbon monoxide fatalities inside homes and in vehicles running inside enclosed spaces, like garages, Hoffman Estates Fire Chief Alan Wax said.

The teens’ case “is very unusual because it was outdoors,” he said.

While deaths in vehicles parked in garages do occur through intentional acts, “we’ve also seen tragic accidents where people forgot to turn their car off, they close the overhead garage doors and go to bed,” allowing carbon monoxide to permeate into the house, Wax said.

That sometimes is linked to vehicles where drivers press a button versus using a key to start and turn off the engine.

“Similarly, we have seen situations where people have a remote start on a vehicle and they accidentally hit the remote start, and it’s close enough to the garage so that the remote start starts the car. And the car’s running in the garage with the door down,” the chief noted.

“A good thing to do is be vigilant — when you go to bed, do a quick check of the garage to make sure the car’s not running.”

Also leave keys in a safe place where buttons can’t be activated unintentionally, he advised.

Meanwhile, “it’s likely the car had a severe exhaust leak,” Chuck Olker, a service consultant at Douglas Automotive in Barrington, said of the March 2 deaths.

Key factors investigators may be considering are the location of the leak, if fumes permeated into the vehicle cabin, whether the exhaust pipe was full-length or shortened, if the car floor was rusty, where the vehicle was parked and wind conditions.

Olker also characterized the accident as unusual.

“We’ve had cars come in with terribly leaking exhaust systems — but it wasn’t getting inside the car,” he said.

Hoffman Estates police said they are looking into possible issues with an after-market exhaust system installed on the vehicle.

Another case of accidental carbon monoxide poisoning inside a car parked outdoors occurred in March 2017 in St. Charles, when two 18-year-olds died. Police said the car's manifold was not connected to the exhaust tail pipe.

“Exhaust emptied into the engine compartment instead of out the tailpipe,” officials said at the time. They also noted the car’s owner had recently worked on it.

Safety tips

The U.S. Centers for Disease Control warns drivers to never run cars or trucks inside an attached garage, even with the garage door open.

With a detached garage, always open the door to let in fresh air if the car is running, the CDC said.

The agency also advises drivers to have a mechanic check their exhaust system annually.

For homes, keep a CO detector near sleeping areas and check the batteries every spring and fall.

GoFundMe campaigns are ongoing to cover funeral costs for the two students. To help Yeferson’s family, visit gofundme.com/f/6xnz7-jefferson-flores. For Litzy’s fundraiser, visit gofundme.com/f/support-litzy-flores-funeral-costs.