Update, 8 p.m. Monday: Power has been fully restored.
According to Xcel Energy, nearly 10,000 people are without power in downtown Denver right now.
We've reached out to Xcel to learn more and will update this story when we hear back. The Xcel outage map shows power is being restored through the evening.
An Xcel spokesperson said the cause of the outages is still unknown.
"Our crews are working as quickly as possible to safely restore service," said Xcel spokesperson Michelle Aguayo. "Once they have returned service to customers, they'll investigate what caused it."