A grandmother from Barbados is dead and two other victims sustained non-life-threatening injuries in a triple shooting on Mattapan Street late Saturday afternoon, Boston police said.

The name of the woman has not been released.

Reports of a shooting surfaced after 5 p.m. Police, ambulances and rows of police tape blocked Mattapan Street. A huge police presence was in the vicinity of the event.

Mayor Martin J. Walsh, Commissioner William G. Gross and Suffolk District Attorney Rachael Rollins went to the scene of the investigation.

“Very sad situation here in a great neighborhood,” said Walsh. “This is a great family that unfortunately experience a very sad loss today. It’s something that when they woke up this morning, they weren’t expecting this to happen.”

“One person, an elderly female, unfortunately was non-viable. God bless her,” said Gross. “We have officers, going house to house clearing every yard and hopes of finding evidence that will help facilitate this investigation. Canvassing for video footage, for witnesses.

“This was an innocent woman struck by gunfire. This should not be tolerated. I know the neighborhood feels that this should not be tolerated, and it shouldn’t. So if anybody has anything that can help us out, please contact us. Our neighborhoods are better than this. This is a time that we bond together and show people that this should not be tolerated. Let’s give this family some justice, let’s give her some justice.”

Rollins vowed to give justice to the family.

“I want to offer this family our condolences, but one of them said ‘we’re sick and tired of prayers.’ And they’re absolutely right,” Rollins said. “They deserve accountability. We have to work harder to make sure that we have a plan about violence and I’m working closely with the mayor and the commissioner about that. You have my words that the best people in our office are here: my first assistant, my chief of homicide — we will be working around the clock to make sure that this family gets accountability. And we are going to work very hard to make sure our homicide numbers are down. This is a beautiful community. This is a strong family from Barbados. Nobody deserves this.These people certainly don’t.”

Late Saturday, as the police presence grew, so did the group of relatives, neighbors and onlookers, some of whom arrived at the corner of the street, frantic, only to crumple in grief, wailing. They were swiftly escorted away from the crowd of media and were met by a trauma team, an occasional cry puncturing onlookers’ chatter. Walsh and Gross each addressed the group in turn, with Rollins offering comfort as well.

The mayor, police chief and DA huddled several times. Walsh at one point asked the media to move back, saying the family “all just found out right now … it’s really bad, it’s really sad.”

Passerby came and went as police, including the Boston Police SWAT team, continued their investigation, carrying equipment back and forth through under lines of police taps. Green cones sat on a portion of the street. At one point a line of officers with two K-9s marched away from the scene.

“It’s so sad,” said a nearby resident named Amy, who declined to give her last name. “They need gun control.”