UPDATE: We have learned a few more details about the migrants' arrival in Denver. Click here to read the latest.
Our original story follows below.
At least 100 migrants arrived in Denver on Monday night without any warning, officials told us, and the city scrambled to turn a rec center into a shelter to give them somewhere to go.
"We got very little heads up that this was going to be happening," Mikayla Ortega, spokesperson for Denver's Office of Emergency Management told us. "People were taken to a homeless shelter."
Officials and immigration activists have been worried about this very scenario. In October, Denver Emergency Management sent 100 cots to a local church for a space set up specifically for migrants passing through town. Some families had already shown up at homeless shelters, which are not equipped to respond to the needs of people who've recently crossed into the country.
The collective of nonprofits who helped set up this dedicated space expected a partisan political stunt, like the one that landed migrants in Martha's Vineyard earlier this year. They also wanted to bring people from the border to help organizations in Texas and Arizona that have been stretched thin for a long time.
U.S. Senator and former Denver mayor John Hickenlooper said in a statement that ""Human lives are not political props. Denver will welcome these migrants with open arms and help any way they can. We will be empathetic to people put in a difficult situation."
While the shelter in the church accepted busloads of people they expected in the last month, Ortega told us the bus - or buses - that arrived on Monday exceeded any existing capacity, so they needed to create extra space.
She added that her office is still figuring out what happened, how many buses showed up in Denver and from where.
"We're not entirely sure," she told us.
Ortega also said her department is hopeful the shelter that Denver helped nonprofits and advocates set up a few months ago will be useful in a future situation like this.
The local chapter of the American Friends Service Committee, an immigrant advocacy group that helped coordinate the shelter in October, posted a statement of support for the city's quick action on their Twitter and Facebook channels. They still need volunteers to help run that original "welcome center," they added.
This is a developing story and will be updated or followed up when more information is available.
Editor's note: This article and its headline have been updated to refer to the people arriving as migrants. A statement from U.S. Senator John Hickenlooper has also been added.