A man died and 10 others were injured, one critically, following a fiery multivehicle collision on the 5 Freeway near Griffith Park that prompted the full closure of southbound lanes for nearly eight hours, snarling traffic Tuesday.
California Highway Patrol officials on scene initially said southbound lanes would remain closed until 10 p.m., but all lanes were reopened before 7 p.m.
Several agencies responded to the Golden State Freeway just north of the Colorado Street off-ramp in Los Angeles just before 11 a.m. to reports of a fiery pileup on the southbound side, according to CHP.
Investigators believe a box truck heading north on the freeway lost control and went over the center divider, triggering the chain-reaction collision on the southbound side, CHP spokesman Jose Nunez said.
The crash ignited a large explosion, sending plumes of thick, black smoke into the air that were visible for miles.
When first responders arrived, they found at least eight vehicles -- three commercial trucks, three passenger cars, one passenger van and a truck -- involved in the collision, Los Angeles Fire Department spokesman Erik Scott said. Several vehicles were engulfed in flames when firefighters arrived.
A total of 75 firefighters from the Los Angeles, Burbank and Glendale fire departments responded to the scene and extinguished the flames, according to Andy Fox, also of LAFD.
One person was pronounced dead at the scene, Fox said at an early afternoon news conference. He said a total of 12 patients were treated, but officials later updated the figure to 11, including the victim who died.
Authorities later said the victim killed was a male adult, and they described the victim in critical condition as a 27-year-old woman. The nine injured others were transported to hospitals. The victims' ages ranged between 22 to 71 years old, authorities said.
A pet dog was also killed in the massive inferno, according to fire officials.
The Los Angeles County coroner's office responded to the scene, and will identify the man killed and determine his cause of death. It was not immediately known which vehicle the victim had been in.
Meanwhile, cleanup took hours.
A big rig, which CHP officials said had been loaded with milk, was completely destroyed in the flames. More than two hours after the collision, the truck's burned-out shell remained across the middle of the roadway.
The crash scene spanned both sides of the freeway, with one vehicle beneath the smoldering big rig on the southbound side of the road, while a pickup truck straddling the median was up against the semi, Sky5 footage showed. A car facing in the wrong direction was lodged under the back of the pickup on the northbound side.
The other commercial vehicle involved, a tanker truck, collided with the big rig and was badly damaged, aerial footage showed.
At least one of the vehicles spilled oil across the roadway, and a hazardous material team responded to clean that up.
All southbound lanes were closed for nearly eight hours, and all but two of the northbound lanes were shut down for most of the day. All northbound lanes reopened just before 6 p.m. CHP had issued a SigAlert for all southbound lanes of the 5 Freeway, just north of Colorado Boulevard.
The crash caused significant delays in both directions of the 5 Freeway, and authorities encouraged motorists to avoid the area and take alternate routes to avoid the traffic congestion.
Southbound traffic was diverted off at the 134 Freeway, while northbound vehicles were directed off at Colorado Street, according to CHP's traffic log.
KTLA's Melissa Pamer contributed to this article.