The clock started ticking at 8:45 p.m. Thursday when a milk tanker truck slammed into a bridge pillar on Interstate 15 in Blackfoot with enough force to nearly topple the overpass.
Twenty-eight hours later, traffic was moving again.
What happened in between was a masterclass in crisis response — engineers working through the night, contractors racing against time, and a team that refused to let East Idaho’s busiest freeway stay closed any longer than absolutely necessary.
The impact of the crash was catastrophic.
The 2026 Kenworth tanker truck’s cab was nearly obliterated, its engine thrown yards into the median. The Riverton Road overpass’ northernmost support pier was bent like a broken bone, pushed several feet out of place and cracked. Guardrails were ripped from the ground and scattered like toys. The pier cap sagged downward, fractured over the central support.
The tanker truck’s driver was ejected by the force of the crash. The 46-year-old Jerome man was airlifted by emergency helicopter from the scene to Eastern Idaho Regional Medical Center in Idaho Falls. He remains in critical but stable condition with a long road to recovery ahead, authorities said.
Within minutes of the crash, ITD Engineer Manager Zak Johnson and Operations Engineer Greydon Wright were en route to the scene. ITD District Engineer Todd Hubbard followed close behind.
One look at the damage and the decision was immediate: shut it all down. Interstate 15’s northbound and southbound lanes were closed to all traffic along with the overpass itself.
Cell phone photos reached ITD State Bridge Engineer Mike Johnson in Boise. He confirmed what local ITD officials already knew — nothing was going to reopen until he could inspect the damage himself Friday morning.
The consequences were instant.
More than 30,000 vehicles a day suddenly had nowhere to go. Traffic choked U.S. Highway 91 through Blackfoot. Miles-long backups stretched north and south on the freeway. Frustrated drivers spilled onto every alternate route they could find.
Late Thursday night, photos from ITD’s Blackfoot office hit Facebook, showing the overpass bridge pillar shattered down to its core. The post exploded — 500,000 views. The community finally understood the gravity of the situation.
Friday morning, Hubbard was already moving pieces into place. Cribbing material from ITD’s Twin Falls area offices. A scissor lift from Soda Springs. A loader and an excavator brought in from elsewhere.
Hubbard, Wright and both Johnsons hunched over plans at ITD’s Pocatello office. Young ITD engineers crowded the doorway, unwilling to miss what was unfolding.
“What an opportunity for these young engineers to learn, right?” Hubbard said later. “By watching closely what happens with this event, they are better prepared for 10, 15 or 20 years down the road. When they see something similar unfold in the future, they’ll be able to say they had seen something like this before and know what steps to take.”
By midday Friday, the full ITD team descended on the crash site to conduct an inspection. The critical question: How close was the overpass bridge to catastrophic failure?
If the central deck fell, it could drag the eastern roadway down with it. That’s why everything underneath stayed closed.
Once the ITD engineers determined the immediate collapse risk was manageable, they had options.
The solution came together in a hastily arranged meeting between ITD engineers, maintenance crews, and contractors from Cannon Builders and Wadsworth Brothers.
The plan: stabilize the bridge using massive 3,000-pound concrete blocks with interlocking grooves, stacked beside the damaged piers like emergency supports.
By 3 p.m. Friday, ITD sent out the message everyone was waiting for: one lane in each direction of the freeway would be back open by mid-morning Saturday.
Cannon Builders worked through the night.
At 12:46 a.m. Saturday — 28 hours after the full shutdown — the first vehicles rolled back onto the reopened Interstate 15.
It wasn’t perfect. Two crossovers near the bridge created a makeshift path, shifting southbound traffic onto the northbound side and back off again. But it worked.
The work isn’t finished. Cannon Builders and A-Core Concrete specialists removed the broken pier and damaged pier cap on Monday. More shoring was moved Tuesday morning into the Interstate 15 southbound passing lane, allowing southbound traffic back onto the driving lane.
Riverton Road won’t see a single vehicle until repairs are complete — likely not until spring.
But Interstate 15 is open. Traffic is moving. East Idaho’s main artery is beating again.
“This was truly a team effort with multiple districts, multiple sheds and multiple law enforcement agencies working night and day to keep Idaho’s traffic moving on I-15,” Hubbard said. “I couldn’t be happier with our response.”
Twenty-eight hours. From catastrophe to solution.
In the world of bridge failures and interstate closures, that’s not just fast.
That’s remarkable.