OSHA is investigating deadly Amazon warehouse collapse after Illinois tornado

New York(CNN Business) The Occupational Safety and Health Administration has opened an investigation into the collapse of an Amazon warehouse in Illinois, after an EF-3 tornado caused major structural damage to the building Friday, a spokesman confirmed to CNN.

At least six Amazon workers died at the warehouse building collapse.

"I can confirm that OSHA has opened an investigation into the building collapse at the Amazon Warehouse in Edwardsville IL due to a tornado. OSHA has had compliance officers at the complex since Saturday, December 11 to provide assistance," said Scott Allen, regional director for public affairs and media relations for the US Department of Labor, in an email Monday.

OSHA, which investigates all workplace fatalities and catastrophes, "has six months to complete its investigation, issue citations and propose monetary penalties if violations of workplace safety and or health regulations are found," Allen added.

A spokesperson for Amazon (AMZN) said in an email Monday that the company is supporting OSHA's effort.

Forty-five people made it out of the Amazon facility, with one person airlifted to a regional hospital for treatment, Edwardsville Fire Chief James Whiteford said during a Saturday evening news conference.

The chief said approximately 150 yards of the building collapsed after the tornado touched down at 8:35 p.m. CT on Friday.

Edwardsville is about 25 miles northeast of St. Louis, Missouri.