MCALLEN, Texas- A Spokane high school teacher was denied entry to a U.S. Homeland Security detention center while on a trip to check the well-being of the minors being held there. 

Mandy Manning is a former national teacher of the year nominee, and Washington teacher of the year. But she's known best for being a high school teacher at Ferris.

For the last several days, Manning has been in Texas working with the American Federation of Teachers and Catholic Charities to check on the minors being detained at part of the immigrant detention center known as "Ursula."

Ursula is the largest of the U.S. Customs and Border Protection detention centers, and has been the spotlight of the discussion surrounding President Trump's border security policies.

On August 14th, Manning and a group of AFT members arrived at the detention center to check on the children being held there, but were denied.

Manning told KHQ the group submitted several applications prior to the visit, but at the last minute they were turned down.

When asked why, Manning said the group was told by agents that "AFT does not have a legitimate mission or business purpose for participating on a visit."

Manning then says the center called the police, and began attempting to tow away AFT member's vehicles.

Randi Weingarten, another member of the group visiting the detention center, tweeted about the experience.

Weingarten said in a tweet that after being denied entry, the group stayed outside the building to pray and hold a vigil for the children.

It was then that officers began threatening to arrest the members. 

Finally, the group moved down the road and held the vigil there. 

The center the group was focused on visiting, the McAllen Border Patrol Processing Center, holds more than 1,000 children at any given time.

Manning is working with AFT, Catholic Charities and a student group called "Beyond the Border" to continue advocating for detained youths.

At Ferris High School, Manning works in the Newcomer Center, a program at the school that works with refugee and immigrant children to teach English.

The purpose of the trip was to also learn more about education at detention centers in the U.S. and the trauma children experience when migrating.

Manning says it's an important part of the work she does because it allows her to learn first hand what the kids she works with goes through before they settle in Spokane.

Manning goes on to say that people might not understand the importance of this as Spokane isn't a Southern border town, but Manning says that's where they are wrong as people who immigrant to the country settle in cities across the U.S.

"We inevitably are going to have kids in our school who have been through the trauma of not only migration, but also being incarcerated once they step foot on United States soil," Manning said.

AFT will continue to apply to entry to the facility, but for now Manning said she is focusing on the upcoming school year and preparing the Newcomer Center for this years students.