HINTON, Iowa | Doris Arndt and some old friends were having lunch at Gringos Mexican Bar & Grille Thursday afternoon when they heard it: a structure-shaking rumble that sounded like it was right above them.
“We thought the building had exploded around us,” Arndt said. “It was almost like a bomb went off. The ceiling -- there was little tiny white stuff that fell on the table in front of me -- it was that hard that it shook.”
The manager of Gringos, which is located about a block from U.S. Highway 75 in Hinton, went outside to find the source of the noise. Arndt and the others soon discovered the thunderous noise had been an explosion at one of the silos at Central Valley Ag, located a few blocks away at 105 E. Main St.
Central Valley was quickly surrounded by firefighters and EMS crews Thursday after the explosion, which occurred around 1 p.m. Traffic on Highway 75 and county road C-60 was stopped for about 90 minutes as the Plymouth County Sheriff's Office and Le Mars, Hinton and Merrill fire departments responded to the call.
Two male employees, who were not identified, were injured in the explosion, Hinton Fire Chief Chad Beck said. Both were taken to Mercy Medical Center – Sioux City. A Mercy representative said both patients were transferred to another hospital.
Arndt eventually made it home, where she watched the flames and smoke from her kitchen window. She and her husband, Gordon, have lived directly across the street from the grain facility for more than 50 years. Gordon had been in the house at the time of the explosion.
"I thought something had wrecked on the highway," he said.
Beck said the crews worked for more than an hour to extinguish flames caused by the blast.
“It took about an hour and 20 minutes,” Beck said. “(There was) a lot of smoke and a lot of dust.”
Trains were also grounded near the site, which is used by Union Pacific, BNSF Railway and Canadian Railway. Traffic was eventually restarted, and Plymouth County Sheriff Mike Van Otterloo said threats of another explosion had “diminished.”
Others who live near Central Valley Ag had similar reactions to Arndt. Monte Hartman, owner of Midwest Computer Systems across the street from the site, said he heard a loud boom and could see the smoke rising from where the explosion occurred.
"I could hear it pretty clear," he said. "I've never seen something like that happen here before."
Hinton resident Crystal Rettinghaus, who lives directly across the highway from Central Valley, was preparing lunch when she heard it. She said the sound woke her sleeping infant daughter.
“It sounded like a semi coming through my house,” she said. “I noticed that there was smoke coming from the building. It was really dark, thick, gray.”
Rettinghaus, who has lived at the house for 13 years, said she’s never seen anything like that happening across the street.
“I remember almost getting evacuated for an ammonia leak here,” she said. “There was another fire that happened that wasn’t as big. It was a little scary."
As of Thursday evening, officials still could not confirm the cause of the explosion. Beck said the state fire marshal was on the scene Thursday evening to determine the cause.
Journal staff writer Mike Bell contributed to this story.