▶ Watch Video: Schools struggle with severe staff shortages

Denver, Colorado — Some school districts are relying on employees to work multiple jobs as they deal with severe staff shortages. In September, 30,000 public school teachers resigned, according to the Labor Department. 

Gel Ortiz often supervises recess at Barnum Elementary School. It’s not her only responsibility. 

“I am principal, assistant principal, teacher, para-professional, I cover classes, lunch recess duty,” Ortiz said. “I do everything that needs to be done.” 

Grace Saenz, who normally works in the school district’s main office, sometimes leads a third-grade class. 

The district’s superintendent told CBS News that everyone is doing multiple jobs. 

“It’s in droves that we’re having absences,” said Denver Public Schools superintendent Alex Marrero. “The real issue here in Denver Public Schools is those guest teachers, and those substitute teachers and those ancillary supports that we do not have.” 

The pool of substitutes has plummeted amid COVID fears from 1,200 to just 375, according to Marrero. It’s not enough to cover those who are out because of stress and illness. To help, the district implemented an unprecedented mental health day for the entire 90,000-student district. 

It’s not just in Denver — burnout is fueling shortages of teachers and staff, like cafeteria workers and bus drivers, across the country. 

Principal Joseph Uy vacuums his Las Vegas elementary school because he’s short on cleaning staff. He’s also teaching. 

The work never ends. 

“Mentally, physically, emotionally, it’s draining,” Uy said. 

The upcoming winter break will offer a few days of rest for staff who are burned out, but most of the academic year is still ahead. 

“We’re going to do what we have to do,” Ortiz said of how her team plans to make it through the rest of the school year. “We have to put our students first.”