Anthony Ochoa peered in the window of Denver Public Library’s downtown location on Wednesday, hoping to use the internet.

Normally, he’s able to stay in touch with family and friends – thanks to the library’s resources.

Instead, he found the doors locked and lights dimmed Wednesday.

Few people milled about the library grounds late Wednesday morning except for a handful of construction crewmembers working on site after the library system announced all 27 locations would be closed after it received an “unspecified threat” last night.

“The library is working with local law enforcement to determine when it is safe for our staff and the public to reopen,” the library said on social media.

Bookmobile stops are also cancelled until the library reopens.

The Denver Police Department was tight-lipped about the incident except to say that the message was sent from outside of Colorado and that a number of similar threats were sent to libraries in other states.

In response to an interview request, a spokesman for the department provided a statement, saying the police are conducting extra patrols around all of the Denver Public library locations.

It was the second time threats forced widespread closures this week. On Monday, four school districts were victim to false active shooter reports, forcing lockdowns at Denver’s East High School, Alamosa High School the Montrose School District and in Colorado Springs. Law enforcement determined the threats were unfounded.

This is a developing story.