(Reuters) -An investigation was underway in Kentucky on Wednesday into what caused an explosion that leveled a Louisville factory, killing two people and injuring several others.
The blast occurred at about 3 p.m. EST (2000 GMT) on Tuesday at a factory owned by Givaudan that makes colors and aromas for the food and beverage industries, according to the company's website.
Two people were killed in the explosion, the company said on Wednesday.
Twelve people were taken to hospitals with various injuries, Louisville Mayor Craig Greenberg said in a statement. The injuries ranged from minor to critical and life-threatening.
The Louisville Fire Department was leading the investigation and a federal reconstruction team from the Bureau of Alcohol Tobacco, Firearms and Explosives will help determine the cause of the incident, Greenberg said.
The blast was heard throughout the city and blew out windows in nearby buildings, local news outlets reported.
City officials said air quality testing was being done at the site, but as yet there was no indication of any danger.
A shelter-in-place order was issued for anyone within a one-mile (1.6-km) radius of the blast. That was lifted about 90 minutes after the explosion, according to the Louisville Metro Emergency Services.