The summer program at Curley Community Center, where a 7-year-old drowned last week after going missing, is expected to reopen Tuesday with a host of new safety regulations in place.

On Monday, counselors and lifeguards gathered at the South Boston facility to review the new protocols, which city officials announced Friday in response to the death of Kyzr Willis of Dorchester.

Kyzr was found in the water about 20 yards from shore, about four hours after he disappeared from the program Tuesday afternoon. Police say the drowning was an accident.

Mayor Martin J. Walsh said the new regulations represent “significant changes’’ to the training and safety guidelines drop-in camps followed before Kyzr’s death. Drop-in camps, unlike licensed summer camps, have until now had few uniform operating procedures, city officials say.

“They had some training beforehand, but we’re more specific about making sure that we have better procedures in place,’’ he said.

The drop-in camp, located along Carson Beach, has two dozen teenage counselors, eight lifeguards, and three adult employees, who typically oversee more than 50 children. The staff reviewed supervision requirements and swimming procedures and brainstormed other ways to improve safety, officials said.

The changes include a mandated head count of children every hour, a requirement that children wear life preservers while swimming, and mandated ratios of children to counselors. Under the new rules, every two counselors will oversee a maximum of 20 children 7 and older, or 10 children who are 6 and younger.

“Before, it could’ve been more, it could’ve been less, depending on the event or the day,’’ Walsh said. “They monitor the kids all day long, but this is an actual, specific count.’’

A camp staff member will be tasked with ensuring that children leave the center only if accompanied by an adult, and children will walk in line between activities, bookended by staff members.

Thirty-four new security cameras should be installed at the community center by Tuesday.

On Monday, some counselors’ parents attended the training session. Will Morales, commissioner of the city’s Centers for Youth & Families, stopped by to speak with them and observe the training.

The parents “wanted to support their kids coming back to work,’’ Morales said. “What we’re trying to do is honor and respect their wishes . . . that they’re supporting their child and the child feels like they’re being supported.’’

While the center was closed, parents dropped their children off at the nearby Condon Community Center day camp. Walsh said he was confident the Curley center would reopen Tuesday, but a spokeswoman for the Centers for Youth & Families said it may fully reopen later this week.

“It all depends on how the young people feel and how the training goes,’’ Sandy Holden said, referring to the younger staff.

Police Commissioner William B. Evans said he hopes the city’s new measures help make programs safer.

“Everything indicates a terrible tragedy,’’ he said. “You let a little kid like that, 7 years old, out of your sight for seconds and something like this happens.’’

The new regulations will be adopted at the city’s five drop-in programs.

“It’s just sad,’’ Walsh said. “Sometimes, it takes a horrific event to bring change.’’

A wake will be held for Kyzr Wednesday at Morning Star Baptist Church in Mattapan. Funeral services will be held Thursday.

Miguel Otárola can be reached at miguel.otarola@globe.com. Follow him on Twitter at @motarola123.