Clayton, N.C. — A blown tire didn't cause a head-on collision on Interstate 40 in Johnston County last week that killed a Smithfield couple, North Carolina State Highway Patrol investigators said Monday.

Terri Lynn Reeves, 20, and Joshua James Witherspoon, 22, died Thursday night when their eastbound 2006 Mitsubishi Eclipse crossed the I-40 median near the N.C. Highway 42 interchange and hit a westbound 2005 BMW X5 SUV and 2005 Lexus.

Their daughter, Shelby Faith Witherspoon, was trapped in her car seat in the back of the Mitsubishi for 20 to 30 minutes. She was listed in fair condition Monday at UNC Hospitals in Chapel Hill.

Reeves' brother said Friday that he feared a temporary spare tire on the Mitsubishi had blown out, causing her to lose control of the car.

Investigators found that all four tires on the car were intact and inflated, said First Sgt. Jeff Gordon, spokesman for the Highway Patrol.

Troopers also ruled out alcohol and excessive speeds as possible causes of the wreck and continue to investigate to determine what happened.

The funerals for Reeves and Witherspoon are scheduled for 8 p.m. Monday at Friendly Chapel Pentecostal Freewill Baptist Church in Benson. Burial will be Tuesday at Fellowship Community Cemetery in Angier.