View photos from the scene

Watch raw video from the scene

Watch News 4 coverage

ST. LOUIS (KMOV) – Firefighters and investigators are still trying to determine the exact cause of Thursday night's six-alarm fire at the South St. Louis County Recycling Center.

It happened around 7:30 p.m. on Thursday in the 4000 block of Bayless Ave.

Authorities tell News 4 that the blaze may have been started by a barrel of paper that generated heat, caught on fire and quickly spread through the plant. No official cause has been determined at this time.

There were 12 people inside that plant at the time of the fire, but they all made it out safely.

The fire did rekindle on Friday morning, but firefighters were able to put it out.

Authorities don't suspect arson at this point.

The company is owned by QRS Recycling based in Louisville, KY.