PHOENIX -- The driver of a truck believed to be at fault in a deadly crash on Interstate 17 on Monday has been arrested, according to Officer Carrick Cook with the Arizona Department of Public Safety.
Joseph Ryan O'Conner, 27, is accused of negligent homicide.
The multiple-vehicle crash was caused by some gas cylinders that fell off of a flatbed truck at about 3 p.m. Monday, according to witnesses. Investigators say O'Conner was driving the truck that was hauling those cylinders.
Investigators said they were able to track O'Conner through witnesses and other leads.
A Chevrolet Suburban attempted to avoid the load by braking, according to the Arizona Department of Public Safety. A motorcyclist following behind stopped suddenly in front of a semitruck. The semitruck hit the motorcycle, forcing it into the Suburban.
Witnesses said they heard four explosions and then saw a ball of fire and smoke in the air.
The fire flash burned the motorcyclist and the semitruck, according to the Phoenix Fire Department.
The motorcycle rider was rushed to a hospital in very critical condition with trauma and burn injuries. He later died, according to Officer Carrick Cook with DPS. He has been identified as Steven Mathew Daniels, 27, of Sun City.
"He was always smiling; the person that was always making everybody laugh," said Randall Bush, a friend of the motorcyclist.
Bush said he actually drove by the crash after it happened but didn't learn until later that Daniels had died.
"We dropped off flowers, had a little memorial, said a couple prayers," Bush said. "(We) went to the accident scene and dropped off things for him there. It's the least we could do."
Friends described Daniels as a "gearhead." He loved to work on cars, drive cars, and ride his motorcycle.
Leroy Smith, a friend of 14 years, said Daniels was a safe rider, always wearing a helmet and biker jacket.
"He was just a very cheerful person," Theo Reece said of his friend. "I miss him a lot. Rest in peace, Steve."
O'Conner is facing felony charges in an unrelated case from October 2013. In that case O'Conner was involved in a gang related assault and shooting, according to court records. Police say O'Conner is a member of the Spartan Riders Outlaw motorcycle gang.
Motorcyclist killed in fiery crash on I-17; driver of flat-bed truck sought
Truck driver from fatal hit and run crash on Monday was arrested by detectives today. Joseph Ryan Oconnor was booked for Negligent Homicide.— Officer Carrick Cook (@DPSOfficerCook) January 23, 2014