GREENSBORO, N.C. -- This year is on track to be the deadliest year yet for car crashes.
Twenty-one people have died so far this year in crashes, compared to 25 in 2016 and 21 in 2015.
A team within the Greensboro Police Department's Traffic Safety Unit is in charged of investigating them all.
The most recent fatal crash in Greensboro happened on Aug. 8 on U.S. 29 south of East Gate City Boulevard. Police say a 21-year-old mother ran off the road and hit a guardrail before coming back onto the road, where her car was hit by another vehicle.
Her 2-month-old son died later that day. Police say the mother is still in the hospital. Her injuries are serious, but they are no longer life-threatening.
When crashes like this one happen, the Crash Reconstruction Unit joins responding officers. If you see this crew on scene, you know it's more than a fender bender.
The CRU responds when crashes are fatal or victims are rushed to the hospital with life-threatening injuries. Their job is to piece together what happened.
"I have a picture of what happened at the end, but I've got to put all the pieces back to what happened at the beginning," said Officer A.D. Reed, with the CRU.
Their investigations shut down roads for hours at a time to document the scene with lasers, measurements and cameras, like at a crash on Aug. 3 at Yanceyville Street and 16th Street. Two people are still in critical condition.
"It's not CSI on TV where within one hour, including commercials, we're able to solve the crime," Reed said.
Only a fraction of their work happens in the field.
"We do have short-lived evidence at the scene," Reed said.
Most of it gets done in the office, where investigators map out the crash on a 3D model.
"If I can rule out that there was no speeding, that helps. If I can rule out there was impairment, that helps," Reed said.
Fatal crashes can lead to serious criminal charges, anywhere from misdemeanor death by a vehicle to, in some cases, second-degree murder.
Reed says it's their job to file charges if necessary, but he says it's equally important to give the victims' loved ones answers and help them find closure.
"As much as there's mangled metal and plastic and things all over the road, and fluids from vehicles everywhere, when we get to the scene, what we mainly deal with is the human element," he said.
Investigations can take several months to complete. Criminal charges are still pending in this month's crashes on Yanceyville Street and U.S. 29, as well as in a fatal crash in May, where three people were killed on I-40 after they were ejected from a vehicle.