Mayor Marty Walsh announced late Monday afternoon that the 2020 St. Patrick's Day Parade, slated for Saturday in South Boston, is canceled.

"This decision is being made out of an abundance of caution to ensure that we are doing what is needed to keep the residents of Boston safe and healthy," Walsh said in a statement.

"While the risk in Boston remains low, this situation is changing very quickly and we are closely monitoring any local cases," the mayor added. "Our top priority is preventing any new cases, to the best of our ability, and we are paying close attention to guidance from public health officials. "

The decision to cancel the parade came abruptly, after days of speculation about whether the event would still take place. Public health experts repeatedly warning people to stay away from large crowds in order to slow the spread of COVID-19.

A tradition dating back to 1902, the parade attracts thousands of spectators and St. Patrick's Day revelers every year. A number of large events across the city have been canceled or postponed, such as the Boston Seafood Expo, in an effort to contain the spread of the virus.

Walsh's statement was issued shortly after Rhode Island Governor Gina Raimondo declared a state of emergency.

The mayor encouraged residents to take preventative measures to stop the spread of disease, reminding people to wash their hands and stay home if they are sick.

New numbers issued by the state Department of Public Health reveal that there are now 41presumed positive casesof the illness in Massachusetts, with one confirmed case.

WGBH News reporter Marilyn Schairer contributed to this report.