Excerpts from abc7chicago.com:

More than 12 hours after smoke alarms first sounded, firefighters were still battling a massive fire that destroyed a warehouse at the Brewster Creek Business Park in west suburban Bartlett.

The fire was at Access, a secure document storage facility at 1200 Humbracht Circle where the warehouse was stacked floor to ceiling with boxes of documents, providing ample fuel for the fire. What workers said began as a few boxes on fire grew into an inferno.

The trouble began around 10 a.m.  when officials said a sprinkler system initially kept the fire in check, but when a series of steel racks being used to store boxes collapsed, there was no saving the warehouse.

In a statement, Access said all its employees evacuated the building and are safe. The company added that it is working with local authorities to determine the cause of the fire.

This from Larry Shapiro:

I responded to the incident around 10:30 a.m. when it was a 2nd Alarm MABAS Box. The MVU was utilized to clear smoke from the warehouse after Bartlett companies had earlier made entry into the building. I mainly photographed the massive amount of apparatus on the scene and they were winding things down releasing everyone but the Bartlett units. At 3:45 p.m. they requested a Box Alarm to the scene for heavy fire.

Larry Shapiro photo