(CNN) Jessica Bailiff looked out at her class and saw empty desks where her students were supposed to be.

The physics teacher's heart sank. She knew why they weren't there.

The day before, federal authorities had swept through a nearby meatpacking plant, rounding up nearly 100 people they accused of being in the United States illegally.

Immigrant rights groups say last week's operation in eastern Tennessee was the largest workplace immigration raid in a decade.

More than 500 students stayed home from school the next day.

Now, a week later, most are back in class. But the community is still reeling, Bailiff says.

Kids who are supposed to be learning about light waves, radio waves and the electromagnetic spectrum, she says, are instead wondering if they'll ever see their loved ones again.

"There's just fear and sadness written all over their faces," Bailiff says.

Teachers become students

The impact of the raid rippled quickly through the community, where immigrants have become a growing part of the population. Children sobbed as they shared their families' stories at news conferences and prayer vigils. And teachers in local schools suddenly found themselves on the front lines of a crisis.

The massive operation at Southeastern Provision in Bean Station, Tennessee, came months after Trump administration officials vowed to at least quadruple work site immigration crackdowns

But last Thursday's raid took many in the community by surprise. In court documents, an IRS special agent says the plant's owners are under investigation for allegedly evading taxes, filing false federal tax returns and hiring immigrants who are in the country illegally. The owners have not been charged and have not responded to requests for comment.

Federal agents arrested 97 immigrants that day, ICE spokeswoman Tammy Spicer said. Most of them face administrative charges for allegedly being in the United States illegally.

As rumors flew and fear mounted about what happened at the plant, activists say local teachers stepped in to help.

Some rode buses home with students that afternoon, said Colleen Jacobs, youth ministry coordinator at St. Patrick Catholic Church in nearby Morristown, Tennessee.

"When the students got to their homes, they weren't sure that there would be anyone there to meet them," she said.

On Friday, about 530 students didn't come to class in Hamblen County schools, Superintendent Jeff Perry said. That's about 5% of the district's roughly 10,000 students, and nearly a quarter of its Latino student population. A typical day might see around 75 absences.

Some of the students who didn't show up weren't directly affected by the raid, said Stephanie Teatro, co-executive director of the Tennessee Refugee & Immigrant Rights Coalition.

"Other families are afraid that if their kids go to school and they go to work, that maybe they won't see each other again," she said.

At a prayer vigil, Esmeralda Baustista holds a photo of her brother Luis Bautista-Martinez, detained in the ICE raid. With her is daughter Yemaya and friend Yaqueline Cruz.

Schools are accustomed to dealing with traumatic events, Perry said, such as the sudden death of a family member or an accident with severe injuries.

But the scale of the immigration sweep, he said, made the impact even more pronounced.

"We've never had anything of this magnitude," he said.

Officials made guidance counselors available, he said, and did everything they could to make sure kids in the district felt safe.

More than 100 local educators gathered at a church on Saturday for a workshop on how to help students through the crisis.

At a session led by immigrant rights activists, the teachers became the students.

They used brightly colored markers to express their emotions on big sheets of white paper:

I feel helpless.

I cried Thursday night, wondering which of my students were without parents.

Most of these children are US citizens.

I do not want to live in a place where people I have known for so long can be taken away from me in a second.

Bailiff, the physics teacher, said it has been devastating to see kids she loves grappling with so much pain and fear.

But there have been encouraging moments, too, like when she's seen students offer words of comfort to their classmates.

Many students are still struggling with their emotions, she says. Some have been in tears. One student shared a message he'd gotten from his mom: If I don't come home from work today, take care of your sisters until we can figure it out.

"It's been very tense," she says. "I've tried to make sure and take the time and talk to each one of them and kind of let them vent."

An elementary school gym becomes a sanctuary

The last time Rita walked through Hillcrest Elementary School in Morristown, she felt lost and alone. That was 10 years ago. Her father had just been deported. She was too scared to tell her classmates. She would just stare out the window, holding onto his red jacket and wishing he'd come home.

On Monday, she looked out at her old school gym and couldn't believe her eyes. This was where she used to run the mile, where she played basketball and dodgeball with friends.

Now it was the site of a prayer vigil for families whose loved ones had been detained in the raid. To Rita, the gym looked just like it did when she was a kid -- with one major difference. It was packed wall-to-wall with people from the community who had come to help.

People packed the gym at Hillcrest Elementary School in Morristown, Tennessee, on Monday for a prayer vigil after nearly 100 people were detained in an immigration raid.

"I felt like I had the support I needed finally after 10 years," said Rita, who asked to only be identified by her first name out of fear for her family's safety.

For days, she says, she's been offering advice to families affected by the raid: Find strength in your pain.

"When I was little and I was sitting (in those) same exact bleachers, you know what I thought, 'I don't have a voice.' But 10 years later, today, standing here in this exact same gym, I know that my voice is powerful," she told the crowd at Monday's vigil.

Behind her, a handwritten sign hung from a basketball hoop, half in English, half in Spanish. "Morristown is 'hogar.' " Morristown is home.

Child after child came to the microphone.

A boy described how his dad, who was detained in the raid, used to make dinner and play soccer with him.

"One time," he said, "he even taught me how to shave, even though I don't have the hair yet."

A little girl stepped forward, her hair in a ponytail, her head unable to peer above the podium.

She handed a letter to a man emceeing the event and asked him to read it:

"My uncle takes care of me when I am sick. He always helps me after school. He takes me places like the mall and helps me with my homework. He's a good person. I feel angry and sad they took him away."

Another child followed her to the front of the room, reading a letter about his uncle. He paused after he finished and looked out at the crowd.

"Thank you," he said, "for hearing me."