Steven Mathew Daniels killed, Maria Robles De Palmonio, Angelica De Palomino injured after multi-vehicle crash and fire on I-17.

A motorcyclist was killed in a fiery chain-reaction crash that closed the southbound lanes of Interstate 17 at Thomas Road through the evening rush hour Monday.

A DPS spokesman Officer said the accident happened around 3 p.m. and the freeway re-opened about 9 p.m.

A large, flat-bed pickup truck, traveling in the fast lane, lost its load - spilling cylinders onto the highway.

The motorcyclist, identified as 27-year-old Steven Mathew Daniels of Sun City, swerved to avoid hitting them and instead slammed into an SUV whose driver had suddenly hit the brakes.

A that point, Cook said a semi-truck carrying limestone slammed into both of those vehicles.

The motorcycle caught fire, which spread to the semi.

Maria Robles De Palmonio, 47, and Angelica De Palomino, 27, both of Phoenix, were in the SUV and suffered minor injuries. Both were wearing seatbelts, according to a DPS spokesman.

The driver of the semi carrying the limestone, Charles Ashe of Chino Valley, was not injured and was also wearing a seat belt.

Police said the driver of the pickup who caused the crash did not stop and they're still trying to locate that person.

"We need to determine if he did in fact know that happened and he made a mistake and continued on," police said. "We need to know if he didn't know. Regardless, the load from his vehicle came off of his truck and that's against the law."

The northbound lanes of I-17 remained open throughout the ordeal, according to the Arizona Department of Transportation.

For about six hours, drivers were forced to exit the southbound lanes at Thomas Road and use alternate routes like State Route 51 to avoid delays - before the closure was lifted around 9 p.m.

"This is one of those situations where I know people are frustrated at the back up," said police. "But, keep in mind that somebody did die out here today. And, our job is to investigate this and notify the family of all the details that happened. It's the least that we can do for them."

DPS is treating this as a homicide investigation.