Multiple firefighters are battling a 4-alarm fire at an old Kmart building in Northeast Portland, according to authorities.

The fire started at the intersection of Northeast 122nd Avenue and Northeast Sandy Boulevard at a building which was once an old spot for a Kmart building, Portland Fire & Rescue shared on Twitter Wednesday morning. At the time when the crew started battling the fire, it was a 2-alarm blaze. However, it quickly escalated to a 3-alarm and eventually to a 4-alarm fire.

Authorities said crews worked to set up a perimeter. According to the fire department, hydrants are limited in the area. However, due to the large parking lot, crews are able to set up aerial operations.

Photos posted by the fire department showed thick plumes of smoke coming out of the building. It is not immediately clear if anyone was injured or the extent of damage sustained by the building at the time of the incident. The Oregon Department of Transportation announced that Sandy Boulevard is closed from 122nd Avenue to 125th Avenue. They said that ash was “raining down” on I-84.

As of 7 a.m. local time, there were 38 units on the scene. All engines were pumping to aerial master streams and had requested additional supply lines. There were also concerned about embers landing in the neighborhood and beginning spot fires or structures.

The cause of the fire remains unknown.

This is a developing story.