(CBS) — A fire that wiped out a west suburban furniture store and warehouse last week — causing an estimated $70 million in damage — was intentionally set by a “disgruntled” employee, federal officials said.

Ruben Antonio Ochoa Cruz, of Joliet, worked as a high lift operator at the RoomPlace warehouse for the past seven months, according to criminal complaint documents filed Friday in federal court. Shortly before the fire started, Cruz was involved in a heated dispute with a supervisor over his attendance at work.

During questioning by investigators, Cruz said he set the fire, using a disposable lighter and a packing slip, because management was “always pushing me.” He stated he lit the fire in order to get rid of tension or stress and calm down, according to the criminal complaint.

Several suburban fire departments responded April 21 to The RoomPlace, 2501 Internationale Parkway, when the Woodridge business caught fire. The 700,000-square-foot complex was soon entirely engulfed in flames and burned for hours. No injuries were reported, but 50 employees were displaced by the blaze.

RoomPlace Arson Complaint by John Dodge

Tom Ahern with with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives tweeted that federal arson charges have been filed against a “disgruntled employee” of the business. Details were not immediately available.

The owners of the RoomPlace have shifted distribution and warehouse operations to a site in Itasca.

“We are deeply disturbed at the news one of our employees has been charged in connection with the fire that destroyed our main distribution center April 21st,” RoomPlace CEO Paul Adams said in a prepared statement. “We continue to cooperate with federal authorities as they search for more details around a cause and potential motive. In the meantime, we remain focused on rebuilding our warehouse and delivery infrastructure and supporting those employees displaced by the fire.”