According to the Arizona Department of Public Safety, the crash happened just before 9:45 a.m. when a westbound semi-truck lost control, hitting the center barrier wall.
The cab of the semi truck went over the wall into eastbound lanes. The trailer remained in the westbound lanes, and the vehicle caught fire.
Witnesses say they had to jump a fence along I-10 to get to victims in semi crash - people were using fire extinguishers to try and put it out. Witnesses describing a trail of fire as the semi slammed on its brakes, then into the wall. pic.twitter.com/j3LcXYfbzb
DPS says the driver was able to escape the truck without being injured.
The truck's trailer was reportedly empty at the time of the crash.
According to Phoenix fire, the biggest challenge for firefighters was securing an adequate water supply. Crews were able to find a hydrant in a nearby parking lot and cut a fence to access it.
Air15 and traffic camera video from the scene showed a massive inferno that engulfed the truck, freeway signs, and some brush along the I-10.
Witnesses told ABC15 crews on scene that they were using fire extinguishers to try to put the flames out before fire crews took over. The roadway was shut down for several hours as workers cleared debris.
Around 1:50 p.m., ADOT officials said westbound lanes of I-10 had fully reopened at 40th Street. Traffic remains heavy in the area, and drivers should expect continued delays into the afternoon.