Another school has been temporarily closed by the city after two staff members tested positive for COVID-19, while concerns over testing lag times continue to grow as the first day of school draws closer.

PS 139 in Ditmas Park has had two cases within the first week and a half of teachers and staff reporting back for classroom preparation, the Department of Education announced Tuesday.

The school’s first case was reported September 11th. The second case was reported Tuesday after the school’s principal called to report the cases to the newly established Situation Room.

“An investigation is underway, and close contacts will be quarantined,” said Miranda Barbot, spokesperson for DOE.

Following the DOE’s protocol for two cases in a school community that aren’t obviously linked to one classroom, the school will be shut for 24 hours.

The PS 139 community will learn more by tomorrow evening about whether the school building will reopen Thursday. While the DOE didn’t explicitly state what happens to the P.S. 139 building during the 24-hour closure, in the spring before schools shut down they cleaned buildings and contact-traced among school communities where cases were reported.

This is the second school temporarily closed after two cases were reported in the same building. On Monday, Mayor Bill de Blasio said overall testing results showed a positive rate of 0.32%, or 55 DOE staffers out of 17,000 tests taken.

Meanwhile, the president of the United Federation of Teachers told reporters he’s concerned about the city’s response to improving testing lags, and he cast doubt on working with the city Department of Health after a tumultuous spring semester before schools were shut down.

As cases started spreading in school communities in the first weeks of the pandemic, the DOH waited too long to work with the DOE on closing schools, critics said at the time. “The DOE delayed closing schools when teachers reported their COVID-19 test results, saying they had to wait until the Health Department ordered it,” the New York Post reported then. “The policy is, if there is no case on DOH record, then it doesn’t exist.”

Feeling burned by the experience, Mulgrew said the new agreement with the DOE hammered out in August to avoid a teachers’ strike specifically eliminates DOH involvement in having to confirm cases “because that's what caused all of the problems in March,” he said in a phone call with reporters on Monday.

“The Department of Health was not confirming cases, which was then causing schools to remain open without...testing and tracing, and we believe [that] led to more and more people becoming sick. So we will not enter into an agreement that says the Department of Health has any jurisdiction over a confirmation of a positive covid case for the city of New York,” Mulgrew said in the call.

A spokesperson for the DOH said the situation in March was very different and the department’s guidance has since evolved.

“The Health Department has made transparency a hallmark of the response and the health and safety of New Yorkers is our guiding light. In the absence of federal leadership and with no national testing strategy, we did everything we could to communicate with the public about what was happening in our city,” said Patrick Gallahue of the DOH in an emailed statement. “The entire health infrastructure of the city has been activated to ensure that teachers, students, families and all New Yorkers have access to the testing and guidance they need to stay safe.

In an interview with Gothamist/WNYC, Chancellor Richard Carranza said the union works with the DOE constantly and that schools will reopen on time. “Michael Mulgrew and I speak multiple times a day, and our staffs are working together every day on multiple work streams. So the work is still continuing to move forward. We have a goal for opening on the 21st as well, that that has not changed,” Carranza said on Tuesday.

Still, Mulgrew said if testing result turnaround continues to be an issue, he’s ready to go to court and stop schools from reopening on Monday: “We're going to have a problem. I have informed the city of this,” he said on the call. “And if it doesn't stop, we're going to take court action.”

He added: "If you asked me if we are ready to open today, I would say we are not."

Brigid Bergin and Jessica Gould contributed to reporting.