This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.

There were no reported injuries in the massive fire that ravaged a commercial building in Glassell Park on Monday, authorities announced.

The Los Angeles Fire Department was alerted about the fire at the two-story structure on 3501 N. San Fernando Road at around 5:20 p.m. The flames sent massive plumes of dark smoke up into the air as some 150 firefighters took part in an effort that lasted nearly seven and a half hours.

Authorities said the building housed a party supply company and was filled with flammable materials. The workers inside the building had to be evacuated, none of whom were hurt, the Fire Department said.

Crews arrived to heavy smoke on the first floor. When crews tried to go upstairs, smoke caused the the fire to ignite and flash, a statement from the Fire Department said.

At some point, firefighters had to go back outside, where downed power lines and unstable walls posed additional danger, the agency said.

Crews managed to stop the fire before it could spread to a nearby medical supply building that stored oxygen tanks, according to the Fire Department.

Arson investigators have not released any information about what might have caused the blaze.