Investigators look into cause of fatal I-10 rollover with toxic spill in Tucson, hazard ‘mitigated’
Feb 16, 2023, 5:02 PM | Updated: 7:26 pm
PHOENIX — Days after a toxic spill caused by a fatal rollover on Interstate 10 in Tucson, investigators were still looking into the cause of the accident.
The single-vehicle crash happened around 3 p.m., closing the I-10 between Kolb and Rita roads for more than a day.
“It appears the truck was traveling eastbound on Interstate 10 when it gradually left the left side of the roadway, into the median,” Arizona Department of Public Safety Captain Ben Bullard said during a press conference on Thursday.
“At which point it got into an uneven section of ground and rolled over onto its left side coming to rest facing east.”
More than 40,000 pounds of liquid nitric acid spilled out of the truck tractor pulling a box trailer, DPS said. The vehicle, which was leased to Landstar-Inway, was traveling to Alabama.
The cause of the rollover is often indicative of a fatigued driver or someone experiencing a medical event that led to the loss of control of the vehicle, according to DPS.
Authorities identified 54-year-old Ricky Immel from Nevada as the driver who was killed in the wreck. His service dog was found by a resident nearby the scene and will be reunited with Immel’s family.
Immel was well within the expected hours of service, but authorities said they were unable to rule out he had been fatigued.
“There may have been a medical issue. We won’t know the outcome of that until the Pima County OME provides the results from their autopsy, which will probably be sometime in the next three weeks,” Bullard said.
High speed, drugs and alcohol have been ruled out as a factor in the collision.
DPS added that though wind could have been a factor in the rollover, there was no way to establish if that would or would not have been the cause.
During the cleanup, the hazardous materials response unit was deployed and found no measurable amount of gas within about a hundred yards of the plume in any direction, DPS said. There was no precise measurement detailing how far the chemical spread.
“This is a gas that’s heavier than air, so it tends to actually land. That night we had rain and we had, also, snow that helped precipitate this down so if you see the color of red, color of yellow, I wouldn’t go tasting it,” Dr. Farshad Mazda Shirazi, medical director of Arizona Poison and Drug Information Center, said during the press conference.
“Again, it’s unlikely that this would have traveled that far.”
The packaging and transport of the hazardous materials were also within Federal Motor Carrier Safety Administration guidelines, DPS said.
“The nitric acid, when it spilled, had a high concentration. When it comes in contact with metals — especially chrome, any metal that has zinc in it, stainless steel — it can release what it known as nitrogen dioxide and nitrogen oxides and that’s that red flume that everybody saw,” Shirazi said.
“That’s actually how we were able to identify within minutes that this was nitric acid until it was confirmed.”
Those standing feet within the spill for longer than “tens of minutes” could develop a delayed respiratory disease about 12 to 24 hours after the incident, according to Shirazi.
Pima County’s health department and poison control center on Wednesday recommended that anyone who may have been in contact with the gas for more than 15 minutes get a medical evaluation if they develop respiratory difficulties like shortness of breath or wheezing. Symptoms could be delayed up to 24 hours after exposure.
