Morning commuters were facing a traffic nightmare early Tuesday after a fiery fatal crash involving a big rig left debris and fuel on south Interstate 805 near Interstate 8 in Mission Valley.

Officials initially said all lanes of south I-805 were expected to be closed in the area for four to five hours as a result of the crash, which was reported around 6:05 a.m.

But before 7:30 a.m., California Highway Patrol officers opened one freeway lane, allowing cars to move past the crash site.

At least one person died in the crash, CHP Officer Michael Meza said.

Meza said it wasn’t clear how many vehicles may have been involved in the crash. Initial reports from witnesses indicated a big rig had crashed, with some drivers reporting it had hit the freeway wall while others said another vehicle was involved.

“There is a fatality involved. The log doesn’t say if it is the big rig driver or (from) another vehicle,” Meza said.

Video of the scene aired by Fox 5 San Diego showed a large plume of smoke coming from a fire that blocked the three right-hand lanes of the freeway span.

He said Caltrans was putting a “hard closure” in place that was to remain in effect for four to five hours.

Meza also said the scene was “deemed a hazmat” but a San Diego Fire-Rescue spokesman said that wasn’t the case.

Capt. Jason Shanley said a Hazmat engine from San Diego Fire-Rescue had responded to the crash, but he said the big rig was carrying a load of almonds and there were no hazardous materials involved other than fuel spilled onto the freeway.

According to the CHP’s online log, San Diego police planned to block off Murray Ridge Road and were sending units to the scene, but “will not be turning vehicles around.”According to the log, all traffic from south I-805 would be diverted to southbound SR-163.

Meza said a number of vehicles were stuck on the freeway between Route 163 and Murray Ridge Road before the one lane reopened.