All residents and staff of Sadler Hall have tested negative for the coronavirus, a Syracuse University official announced Sunday.

SU detected “a very weak signal” of COVID-19 in Sadler Hall’s wastewater on Friday, leading the university to test all residents and staff for the virus. Sadler Hall was the second SU building to show traces of COVID-19 in its wastewater, following Ernie Davis Hall, whose residents also tested negative.

“I want to thank the residents and staff of Sadler Hall for taking the time to visit the Quad on Friday to be tested,” said Vice Chancellor Mike Haynie in a campus-wide email. “We will continue to sample wastewater in Sadler Hall and facilities across campus and respond to what we learn with swift action appropriate to safeguard the health of our campus and the Central New York community.”

The university did not require residents of Sadler Hall to quarantine during the testing process. Residents of Ernie Davis Hall, where stronger signals of COVID-19 were present in its wastewater, had to confine themselves to their floors and have their meals delivered while waiting for their test results. All residents and staff of Ernie Davis had tested negative on Friday, when SU lifted the quarantine.

SU’s wastewater surveillance program tests sewage from 24 points across campus two times each week.