An under-construction apartment complex in Concord caught fire early Tuesday morning, forcing the evacuation of 250 people. The fire started at 1 a.m. at Clayton Road and Galindo Street, engulfing the 180-unit Renaissance Square Phase 2 project from Legacy Partners and SyRES Properties. The 260K SF project was 60% completed and was expected to open in the summer, KTVU reports.

The entire building was taken out, one side collapsed and another side is expected to collapse, Contra Costa County Fire Marshall Robert Marshall told KTVU. He said the project was in the stick-frame phase of construction, which allowed the fire to move quickly.

Residents of the complex across the street were evacuated as a precaution. Two people were taken to the hospital to be treated for smoke inhalation. The fire was under control as of 5:15 a.m., according to the East Bay Times.

At this time, there is no word on what caused the fire. Due to the heat of the fire, fire officials don’t expect to be able to begin investigations for 24 hours, according to ABC7News.

In the last 18 months a handful of fires have struck several under-construction projects in the East Bay. In July, a fire destroyed the 193-unit Alta Waverly project in Oakland, but investigators could not pinpoint a cause. In May, a fire destroyed a mixed-use project at 3800 San Pablo Ave. in Emeryville less than a year after another fire hit that project. Arson was suspected in the Emeryville fires.