(KTEN) — Four Marietta residents died in a Saturday night crash in the southbound lanes of Interstate 35 between Ardmore and Marietta.

The Oklahoma Highway Patrol said the victims were all in a Honda Civic which collided with an 18-wheeler just before 6:30 p.m. They were identified as:

  • Reginaldo Fernandez Martinez, 36, the driver
  • Marisa Sanchez, 35
  • A one-year-old boy (name withheld)
  • A four-year-old boy (name withheld)

OHP said the cause of the fatal crash remains under investigation.

Christopher Sneed was driving his big rig south on I-35 when he approached the scene shortly after the crash.

"I saw the car in the middle of the highway and smoke billowing out of it," he said. "I jumped out to see if anyone needed help."

Sneed said it appeared that a smaller vehicle had crashed into an 18-wheeler. An off-duty police officer asked if Sneed could assist as flames began to break out.

"So I pulled my fire extinguisher from my truck, and I went over there and I put out the fire," Sneed recounted. "Upon putting out the fire, I noticed there was four deceased individuals [in the smaller vehicle]."

As a former volunteer firefighter, Sneed said he's worked at crash sites before.

"This was the most horrific accident that I've ever witnessed," he said.

The Oklahoma Department of Transportation said traffic was detoured to US 77 at Exit 24 in Carter County, rejoining I-35 at Oswalt Road in Love County. The southbound lanes of the freeway were closed to traffic for almost 12 hours after the accident.

ODOT reported that southbound traffic was not restored until 6 a.m. Sunday. 

"I would like everyone to be more cautious around truck drivers," Sneed added. "We just can't stop on a dime."