A massive explosion Tuesday at a food coloring factory in Louisville, Kentucky, killed two people and injured a dozen others as smoke billowed from torn metal structures and debris.

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

For some Louisville residents, the incident brought back memories of another deadly explosion at the same location 21 years ago.

Here’s what you need to know.

What happened?

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

12 people were injured and taken to hospital according to the mayor’s office. As of Wednesday, three people were hospitalized with non-life-threatening injuries, according to a spokesperson for the University of Louisville Hospital.

It is not yet clear what caused the explosion. Louisville officials described the incident as a “large-scale incident” involving hazardous materials, with federal agents assisting fire investigators.

“We do not have any reason to believe there is any nefarious activity at this time,” said Shawn Morrow of the Bureau of Alcohol, Tobacco, Firearms and Explosives.

Givaudan said in a statement that they are “in the early stages of investigating the cause of this incident and are cooperating with first responders and support organizations.”

CNN reached out to Givaudan on Wednesday for further comment.

Who were the two victims?

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

The identities of the victims have not been publicly disclosed.

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

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

“The business had told us that all employees were accounted for,” Greenberg said at a news conference. “Unfortunately, that wasn’t the case.”

Is it safe now? What about nearby residents?

Immediately afterwards, people within a 1-mile radius of the plant 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.

As of Tuesday afternoon, the shelter-in-place order was lifted, but the mayor still urged residents to exercise caution.

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

He added that after using drones to monitor air quality in the area, “we found no evidence of anything hazardous being released.”

Has this happened before?

The facility suffered a deadly explosion more than two decades ago, while under different ownership.

Previously, the food coloring facility was owned by DD Williamson & Company, which was acquired by Givaudan in 2021 and renamed Givaudan Sense Colour.

On April 11, 2003, a “processing vessel overpressurized” at the DD Williamson plant, releasing 26,000 pounds of aqueous ammonia into the air and blowing debris up. US Chemical Safety and Hazard Investigation Board.

The explosion forced 26 residents to evacuate and 1,500 others to seek shelter. Also dead was 44-year-old worker Louis Perry, whose grandson Lorrie Hibbard told CNN on Tuesday that the latest explosion brought up memories of the accident.

“And after one explosion you would think it wouldn’t happen again. But here we are,” Hibbard said. “All I heard was there was another explosion at the facility, and that takes you right back to 2003.”

The company was fined $10,000 by the Kentucky Labor Cabinet for the 2003 explosion, according to the report. Occupational Safety and Health Management.

Although the cause of Tuesday’s explosion has not been determined, the fire chief said they believe it was not the same material as the 2004 explosion. “This was related to solid anhydrous ammonia, which was no longer on site,” O’Neill said.

CNN’s Emma Tucker, Kia Fatahi, Taylor Galgano and Andy Rose contributed reporting.

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