A two-alarm fire damaged a paper-shredding and recycling company Tuesday night at 710 Thomas Ave S.W. in the south Renton’s warehouse district.

An employee of DB Secure Shred called 911 and the alarm company reported the fire at just after 7 p.m. The worker attempted to put out the fire with a fire extinguisher.

The fire was upgraded to two alarms after responding crews saw the extent of smoke coming from the building, said Deputy Fire Chief Bill Flora. Crews from the Tukwila Fire Department responded.

The cause of the fire was officially undetermined, Flora said. A damage estimate wasn’t available mid-week. There were no injuries.

“All indications point to a deep-seated, smoldering product (shredded paper) brought into the business, which ignited when the evening worker opened the large roll-up door as he started his shift,” he said.

The fire involved shredded paper next to a piece of equipment, said Flora.

It occasionally happens that a spark from some source will ignite shredded paper, Flora said. The fact the paper caught fire was not intentional, he said.

The sprinkler system kept the fire under control. Fire crews then used hoses to fight the remain fire; equipment was used to move paper around to search for embers.

“If the sprinklers had not contained the fire, there were enough combustibles to have taken off and caused a lot of damage in the building,” said Flora.