Shelby County, TN – It was a tragedy averted.

Four lives were saved Wednesday, because of the persistence and vigilance of a loved one.

“A carbon monoxide event doesn’t happen very frequently, but when it does, it is very serious,” said Shelby County Fire Dept. spokesperson, Brent Perkins.

The fire department spent the morning making sure the home on Rolling Green Drive was safe after two adults and an 18-year-old boy and 10-year-old girl were found near death, because of exposure to the deadly gas.

“The level of patient care required when we made the scene told us that these individuals did not have much longer,” said Perkins. “It was a very serious call.”

Luckily for the family, a loved one was trying to call them.

When she couldn’t get in touch, she came to the house and forced her way inside.

Had she not, authorities say the family could have likely been dead within 30 minutes.

A neighbor was told by an MLGW employee that the carbon monoxide came from a carrunning inside the closed garage.

Perkins could not confirm, “At this time we’re still trying to determine the source and get a clear picture on how long they may have been in there.”

With four lives spared, Perkins says this is a good reminder for everyone to make sure their home has a working carbon monoxide detector.

“If you’re going to get one, get a U.L.-approved carbon monoxide detector and if you’re confused, give us a call,” said Perkins. “We’ll come out and make sure its put in properly.”

All four victims are expected to make a full recovery.