NEW YORK CITY (NewsNation Now) — Students and parents are joining back-to-school rallies across the country, pushing districts to ease up on remote learning and fully reopen schools. But teachers and their unions are pushing back, worried many simply aren’t ready for in-person learning.

There’s evidence they may be right. Staff members at several schools have been diagnosed with COVID-19 since the academic year began last month. At least three cases have been fatal.

New York City schools are set to reopen next Monday, and nearly half the students in the nation’s largest district have opted for all-remote learning. 

So far, 55 New York Department of Education employees have been diagnosed with coronavirus. The district says that’s out of nearly 17,000 workers tested, or a positivity rate of about .32 percent. New York, once the epicenter of the pandemic, has maintained an infection rate below 1 percent for 38 straight days.

“In fact, we’re the envy of the nation when it comes to the health care situation. We’re one of the safest places in the country right now,” said New York City Mayor Bill DeBlasio. “People are looking at the fact that our school system is coming back..and they’re amazed.”

The city’s largest teacher’s union says it’s less than amazed with the state of readiness for reopening. It struck a deal with the city two weeks ago to avoid a strike, and some members now say the administration isn’t living up to its part of the bargain.

It’s a similar refrain across the country. 

NewsNation reporters were at back-to-school rallies Tuesday in western New York, Pennsylvania, Tennessee, and suburban Chicago— all demanding more classroom days to start the school year. Yet elsewhere in the country, teachers are expressing serious concerns about the state of readiness.

Austin, Texas teacher Nicole Lee says she loves her job but had to quit, saying the coronavirus threat is just too high to risk infecting her family.

“I’m a public servant,” she said. “I love giving back to my community. But I have to be selfish in this situation.”

She’s not alone. A growing number of teachers are reporting concerns about ventilation, cleanliness and the level of testing being done by school districts nationwide. Despite the push for more in-person learning, many say they may stay home until they’re sure they can return to school without worsening the COVID pandemic.