SACRAMENTO (CBS13) – Firefighters battled a large fire at an apartment complex in Sacramento overnight.

The fire broke out just after 9 p.m. Sunday night at River Terrace Apartments on West El Camino Avenue near Millcreek Drive in the Natomas area. Firefighters say the flames started in a downstairs unit and then spread to at least three nearby apartments.

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A Sacramento Fire Departement spokesperson on the scene said traffic from the nearby Aftershock concert made it difficult for firefighters to get to the fire.

“There were about 1,000 people exiting the Aftershock venue, so we had some access problems thanks to traffic, foot traffic, people on the ground who are more curious to see what’s happening than they are in helping get out of our way to make our attack on the fire,” he said.

Everyone made it out of the apartments safely.

There is no word on what started the fire.