Twenty seniors at Ferris High School are self-quarantining after possibly being exposed to the novel coronavirus at their internship in Downtown Jersey City, Superintendent Franklin Walker said.

Walker said the students are interning at Pershing LLC, a subsidiary of the Bank of New York Mellon, where an employee has tested presumptive positive for COVID-19.

“All we know at this time is the individual worked for that company and our students were in the same building at this point and time,” Walker said. “Based upon that indication and in collaboration with the health department that the students should just remain home and self-quarantined.”

Pershing LLC did not respond for comment on the employee. Jersey City officials said there were no confirmed cases of coronavirus as of Thursday.

The students are part of a co-op program that allows them to attend classes during the day and spend the afternoon working in the office for credit.

Walker added that six of the 20 students worked on the same floor as the man. The students will not return to school for at least two weeks.

Gov. Phil Murphy announced Wednesday that New Jersey has a total of 29 cases of coronavirus, including one in West New York. Murphy declared a state of emergency Monday amid growing concerns about the spread of the virus throughout the state.

COVID-19, the illness caused by the novel coronavirus, has sickened more than 1,400 people nationwide and led to at least 38 deaths.

The Jersey City school district sent students home for a half day Wednesday so teachers could start preparing three weeks’ worth of home instruction for the 30,000 students in the event that schools close.

The decision to close schools is made by the district’s superintendent in consultation with health officials. Districts can go ahead and close their schools if they receive a written directive from the state Department of Health or the health officer of the jurisdiction to institute a public health-related closure.