SAN BERNARDINO ( — Tens of thousands of Southern California Edison customers across San Bernardino spent much of Monday without power.

By 11 p.m., CBS2 Inland Empire reporter Crystal Cruz said 6,500 customers were still in the dark, with SCE unable to say when service would be restored. Shortly after a transformer exploded at a substation at Waterman Avenue and Second Street, there were about 20,000 customers without power.

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Video shows a black cloud of smoke above the substation following the explosion, which occurred around 2 p.m.

Marcello De La Cruz kept watch over the Chevron gas station he manages in San Bernardino to make sure nobody tried to break in Monday night.

“Just keeping watch for trespassing or something like that,” he said.

Both the fire and police departments were busier than usual on Monday night, fielding calls for help, including a minor crash near a freeway off-ramp.

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“It’s been hectic, it seems like everybody is just forgetting to drive defensively and we’re responding to a lot of collisions at several of our major intersections,” said San Bernardino police Officer Jose Castro.

Food 4 Less used a generator to turn the power back on for customers in need of a few things to help them see in the dark.

“They are coming in and getting candles, and food too, a lot of people are shopping for food,” a store official said.

Meanwhile, holiday shoppers looking to run into Ross had to settle for gifts at the grocery store.

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“I was planning on going to one of these stores to do my last Christmas shopping, because I haven’t even gotten my niece, but I can’t even do that now because everything is closed down,” said Veronica Zaragoze.