BOSTON — Mayor Marty Walsh has declared a public health emergency in the city in response to the outbreak of COVID-19, the disease caused by the novel coronavirus.

The declaration allows city officials to deploy all the resources and personnel necessary to meet the needs of the moment, and it will also authorize them to issue additional directives as the situation develops.

As of Sunday, there are 29 total COVID-19 cases among Boston residents. Walsh said city officials expect that number to grow and that they are preparing accordingly.

"This is a time of shared sacrifice and I know first-hand that we are capable of that here in the city of Boston," Walsh said. "The bottom line is that social distancing is not a vague, wishful strategy. It is backed by science and data.

"What we do in our city over the next week or two will make big impacts on the local trajectory of this outbreak and our hospitals' ability to handle it. It will save lives."

On Friday, Walsh and Boston Public Schools Superintendent Brenda Cassellius announced the closure of all schools beginning Tuesday.

Boston schools are expected to reopen April 27, following April vacation, but Walsh said there is a chance schools could reopen sooner if it is safe to do so.

Nearly all schools will be open Monday for children to gather their books, belongings and school lesson plans. The two exceptions are the Eliot School and McKinley School campuses, which will remain closed Monday. A nonstudent member of the Eliot School community tested positive for COVID-19, and a nonstudent member of the McKinley School is currently being tested for COVID-19.

While schools are closed, Walsh said food will be made available to the families of children who rely on the free meals provided by Boston Public Schools. Starting Tuesday, families can pick up food at various designated locations in the city, which can be found by clicking this link.

Walsh also ordered Boston bars, restaurants and nightclubs to reduce their capacity by 50%, remove tables and chairs to reflect reduced capacity, follow social distancing guidelines and not allow lines to form outside. Those establishments have also been ordered to close at 11 p.m.

Any violations of these mandates could result in a 30-day closure. The city will lift regulations for restaurants and bar rooms that serve food in order for those establishments to serve takeout food. Boston officials are encouraging residents to use delivery services.

Beer gardens in Boston will be shut down until the public health crisis in the city has ended, Walsh said.

Walsh's public health emergency declaration came on the same day in which the canceled 2020 South Boston St. Patrick's Day Parade would have been held.

In a statement, Walsh said the decision to cancel the parade was 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."

On Friday, the Boston Athletic Association and city officials announced the postponement of the 2020 Boston Marathon, which is now scheduled to be held Sept. 14.

Bar and restaurant owners in South Boston agreed to voluntarily close Sunday in order to help prevent the spread of COVID-19.

People packed the bars in the Boston neighborhood Saturday night, despite requests from Walsh and Massachusetts Gov. Charlie Baker to adhere to "social distancing" guidelines.

The Boston Licensing Board worked closely with the licensed establishments in South Boston regarding the influx of people due to it being St. Patrick's Day weekend and the ongoing public safety concerns surrounding COVID-19.

About an hour before Sunday's announcement was made, dozens of people were waiting in line outside South Boston bars to celebrate St. Patrick's Day, which is Tuesday.

According to the U.S. Centers for Disease Control and Prevention, the recommended safe distance to help prevent the spread of COVID-19 is 6 feet.