AURORA | A gut-wrenching fatal crash last month that left a 3-month old baby and her grandfather dead shed light on a tough reality for police: Car seats can save lives — and they regularly do — but too many are incorrectly installed.

“Almost always there is some adjustment that can make it better,” said Aurora police Lt. Jeff Turner, who oversees the department’s traffic section.

In the April 28 crash that killed Kataley Ramerez-Cespedes and her grandfather, Jaime Humberto Ramerez-Lopez, 40, police said the infant’s car seat wasn’t correctly installed.

Turner said he couldn’t discuss exactly what was wrong with the seat’s installation, citing the ongoing investigation into what caused the crash. But, Turner said, investigators believe it was installed in Ramerez-Lopez’s SUV incorrectly.

And experts say incorrect installations are a far more common problem than many parents realize.

According to local hospitals and police, more than 90 percent of car seats that police and hospital car seat technicians see are incorrectly installed. The National Highway Traffic Safety Administration says three out of every four children are in an improperly installed seat, which aren’t as safe as they could be.

Turner said the bulk of the mistakes are fairly minor, things like failing to cinch down the seat belt hard enough. When police see a child who should be in a car seat but isn’t, or a child who isn’t in a seat belt, they always write a ticket, he said, but those cases are rare.

“Most of the time, if somebody is using them they are at least a step in the right direction,” he said.

The seats might seem fairly simple to install, but Turner said it’s important that parents understand how the seat works.

“Car seats can be a little complicated, so certainly people need to take the time to make sure they are adjusted right and secured in there right,” he said.

Selena Silva, education coordinator at Children’s Hospital Colorado, said one of the easiest things parents can do to make sure their child’s car seat is correctly installed is read the owner’s manual for both the seat and the car.

“That can help you avoid a lot of fatal mistakes,” she said.

But parents need to read those manuals closely, and even take notes or call for help on parts they don’t understand, she said.

Common mistakes parents make include failing to use the “top tether” on a forward-facing seat. Those tethers typically go over the vehicle’s seat and anchor the car seat more snugly to the car.

Another crucial mistake parents make happens when the child “graduates” from that first infant seat into a second one. When a child is born, hospitals typically help a parent make sure the first seat was installed properly, but parents don’t always seek out assistance with the second seat, she said.

Children’s has a phone number, 720-777-4808, that anybody, not just patients there, can call to get help installing their seat.

The good news, Silva said, is that car seat’s work well when installed properly, and they continue to make children safer.

“Car seats are working,” she said. “They continue to reduce the risk of dying in those first two years of life.”

Free car seat safety check May 11

What: Experts will help install your car seat, or make sure the seat you have is installed correctly.

When: from 10 a.m. to noon Saturday May 11.

Where: Aurora Public Schools Administration Building, 1085 Peoria St. (corner of East 11th Avenue and Peoria Street).

Who: Aurora police, Children’s Hospital Colorado and the Colorado Department of Transportation.

Note: Bring your child along so experts can make sure the seat fits them correctly.

For more information, call 303-739-6374