Residents of the Crockett area in California heard roaring noises and witnessed smoke coming from the co-generation power plant near the C&H Sugar Factory on Monday.

People in the area were awakened late Monday night, a little before 11 p.m. local time (2 a.m. EST) by loud roaring noises along with huge clouds of steam or smoke. The sounds continued for almost 15 minutes and emergency response took control of the situation.

Llocal reports suggested that the loud noise and steam were the result of a “safety valve malfunction”. It was unclear if it poses an immediate threat to the residents. The reports also said that minutes before the loud noises were heard, there was a mild earthquake. It was a 1.8 magnitude tremor, according to the United States Geological Survey.

No immediate statements were issued by the responders but the Benicia Police Department tweeted, “Benicia dispatch has been inundated with calls in regards to a loud noise. C&H factory is working an incident. No further information available at this time.”

They later added, “Noise update: There is a steam release coming from the Cogen (next to C&H). Noise is expected to last 20 more minutes".

This is a developing story.

natural gas plant smokestack
In this representative image, steam and exhaust rise from the smokestack of a natural-gas powered power plant on Jan. 22, 2019, in Berlin, Germany. Sean Gallup/Getty Images