CNN
—

A massive explosion at a food dye plant in Louisville, Kentucky, on Tuesday left two dead and a dozen others injured as smoke billowed from torn metal structures and rubble.

Both victims were workers at the Givaudan Sense Color factory, which produces food and beverage dyes and is owned by Swiss manufacturer Givaudan.

For some Louisville residents, the incident revived memories of another deadly explosion that occurred at the same location 21 years ago.

Here’s what you need to know.

The explosion occurred around 3:00 p.m. and was felt miles away in Jeffersonville, Indiana, according to CNN affiliate WLKY. It was extremely loud and blew out the windows of several nearby businesses, WKLY reported.

Twelve people were injured and taken to hospital, according to the town hall. As of Wednesday, three were still hospitalized with non-life-threatening injuries, according to a University of Louisville Hospital spokesman.

It is still unclear what caused the explosion. Louisville authorities described it as a “large-scale incident” involving hazardous materials, with federal agents assisting fire investigators.

“We have no reason to believe at this point that there was any type of nefarious activity,” said Shawn Morrow of the Bureau of Alcohol, Tobacco, Firearms and Explosives.

In a statement, Givaudan said they are “in the early stages of investigating the cause of this incident and are cooperating with first responders and supporting agencies.”

CNN reached out to Givaudan on Wednesday for further comment.

In a statement, Givaudan said two “team members” died in the explosion.

The victims have not been publicly identified.

“We mourn with the families, friends and loved ones of those who have been lost and injured during this very difficult time,” the company said.

One of the victims was found in the rubble hours after the company initially said no employees were missing, according to Louisville Mayor Craig Greenberg.

“The company has told us that all employees have been accounted for,” Greenberg said in a news conference. “Tragically, that was not the case.”

Aerial footage shows the scene above the explosion in Kentucky

Immediately afterward, people within a 1-mile radius of the site were ordered to shelter in place — except for homes in the two blocks surrounding the plant, which were ordered to evacuate because their windows were blown out.

By Tuesday afternoon, the shelter-in-place order had been lifted — but the mayor still urged residents to be cautious.

“We are now dealing with an unstable building that has partially collapsed and may continue to collapse,” said Louisville Fire Chief Brian O’Neill.

He added that after using a drone to monitor air quality in the area, “we found no evidence of any release of anything dangerous.”

The facility had a fatal explosion before, more than two decades ago, when it was under different ownership.

Previously, the food coloring facility belonged to DD Williamson & Company, which was acquired by Givaudan in 2021 and changed its name to Givaudan Sense Colour.

On April 11, 2003, a “process vessel became overpressurized” at the DD Williamson plant, releasing 26,000 kilograms of aqueous ammonia into the air and sending debris flying, according to a report from US Chemical Safety and Hazard Investigation Commission.

The explosion forced 26 residents to evacuate and 1,500 people to shelter in place. It also killed 44-year-old worker Louis Perry, whose granddaughter Lorrie Hibbard told CNN on Tuesday that the latest explosion brought back memories of the accident.

“And you’d think after one explosion it wouldn’t happen again. But here we are,” Hibbard said. “All I heard was that there was an explosion at the factory again and it’s taking you back to 2003.”

The company was eventually fined $10,000 by the Kentucky Department of Labor for the 2003 explosion, according to Occupational Safety and Health Administration.

While the cause of Tuesday’s explosion has not been determined, the fire chief said they believe it is not the same material as the explosion in 2004. “This dealt with a solid anhydrous ammonia that is no longer on site,” O’Neill said.