IWILEI (HawaiiNewsNow) - It was a chemical clean-up gone wrong. An explosion Friday afternoon, rocked Iwilei and forced evacuations at Dole Cannery.
Honolulu investigators are still trying to find the exact cause of the explosion, but they've narrowed it down to two possibilities.
There were no flames, yet firefighters battled to douse the ground with water, and cool the soil to stop an invisible threat.
Investigators say vapors from a chemical reaction underground led to three explosions.
"It was more startling than anything. It didn't like shake where I was, but it was super loud," said Zach Payne, who works at Dole Cannery.
"That kind of shook our building a little bit. We didn't know what it was at first. It could've been an earthquake we thought, or something like that," said Dale Machado, an employee at KSSK Radio, which is located at Dole Cannery.
Sky News Now got a view of the vacant lot on Pacific Street and Iwilei Road, the future site of a Lowe's store.
It's just as large as the Dole Cannery building next door.
Everyone inside was evacuated.
"After a while we started seeing smoke from those pipes that are down there," said Payne.
Firefighters say six workers were decontaminating the soil through remediation.
It's a process where they inject a chemical into the ground to break down the hazardous compounds.
That produces a gas, which is captured and burned.
But around 1:30 p.m., something went wrong.
The Honolulu Fire Department says one of two things may have caused the reaction.
Either something ignited, or overreacted.
"That flammable gas and the oxygen which is flammable, or just the pressure build-up of any of the gases in the container which is piping, could all have led to the explosion," said Capt. Terry Seelig, Spokesperson for the Honolulu Fire Department.
Paramedics checked the workers, but they did not need to go to the hospital.
Seelig says they're with Westin Solution, a large worldwide corporation.
Crews did not detect any more gas, so for now, investigators say it appears the chemical reaction has subsided.
The Honolulu Fire Department has turned things over to Westin Solution.
Seelig says the company will fly in an investigator from the mainland, so it could take at least a few days before the cause of the explosion is known.