KALISPELL, Mont. -

An investigation is underway after a workplace fall took the life of an employee in the Flathead. It happened at the Walmart in Kalispell and investigators from the Occupational Safety and Health Administration are looking into it.

An OSHA representative tells us the employee was standing on a moveable staircase when he fell. It's not quite a ladder, but rather a staircase with wheels.

The man reportedly fell while rearranging merchandise. Some witnesses say he wasn't found until 20 minutes later, OSHA has not confirmed that report as the investigation is ongoing. He died from his injuries at the hospital.

"We go out, we open an inspection, we look at the material evidence, we do employee interviews, we perform a fact-finding investigation to determine what happened," said Area Director for OSHA Jeff Funke, in a phone interview.

Details about the accident itself are slim. OSHA can't release information about the employee, like his name or age, or even what part of the store he was working in.

We placed a call to the store but managers had no comment. They referred us to Walmart's media relations line. A representative got back to us several hours later and issued this response via email:

"Our thoughts and prayers are with the family and friends of our associate during this difficult time. We work hard to provide a safe environment for all of our associates, and we will continue to work closely with OSHA as they look into this tragic accident."

Funke tells us Walmart is being cooperative with the investigation and at this point has followed their policies.

"There's a federal law that when an occupational fatality occurs that the employer must report that to an OSHA office within eight hours and they did that," said Funke.

Now investigators will work to piece together what happened and help the store figure out how to prevent it in the future.

"We're going to find out the facts here. We're going to make sure they're true and accurate and we're going to determine if there's a violation of an OSHA standard," said Funke.

OSHA investigators have six months from the date of the incident to finish their investigation.