SACRAMENTO, Calif. (AP) — A substitute teacher in the Sacramento City Unified School District has died after contracting the coronavirus, the district announced Monday.

The teacher died on Sunday, according to a district statement. It didnt indicate how the teacher might have become infected with COVID-19.

The instructor, who also was a temporary volunteer, worked at Sutterville Elementary School in February.

Sacramento County's website was updated Monday to show that 2 people had died and that both were older than 70 and had underlying health conditions. The first death in the county was a woman in her 90s who lived at an Elk Grove nursing home. The county now has 33 confirmed cases of coronavirus.

Mayor Darrell Steinberg called the death tragic.

“This death underscores the seriousness of this current public health emergency. Sac City Unified will continue to implement any and all measures recommended by public health leaders to protect the health and safety of our students, our staff, and our community,” Superintendent Jorge Aguilar said in a statement.

“This is a devastating loss to our community,” David Fisher, president of the Sacramento City Teachers Association and a second-grade teacher, said in the joint statement. “Our schools are filled with young people, but it’s important to remember those in our school community are also older and perhaps more vulnerable at the time of this virus crisis.”

The district has about 50,000 students. Beginning Monday, the district closed all 81 schools for two weeks. Sutterville and four other campuses were cleaned and disinfeçted out of concern that some people might have been exposed to people with the virus.

Many other districts around the state also have closed schools, some for up to five weeks, in an effort to control the spread of the virus, and some are making plans for online classes.