Last Updated Mar 25, 2019 9:11 PM EDT
Another survivor of the Marjory Stoneman Douglas High School shooting in Parkland, Florida, has died. Police call it an "." It is the second suicide in about a week. On March 17, , a recent graduate of Stoneman Douglas, took her own life. So far police said they've found no link of Saturday's death to Aiello, reports CBS News correspondent Manuel Bojorquez.
Last February, 17 students and staff were killed during the shooting. With survivors still living with the trauma of that day, officials and parents are now redoubling their efforts to prevent more lives from being lost.
Community leaders and residents met Sunday to confront the newest tragedy rippling across Parkland.
"You must communicate with your children, and children, you've got to talk to your friends," said Cindy Arenberg Seltzer, president of the Children's Services Council of Broward County.
"We tried to get the warning out last year," said Ryan Petty, whose daughter Alaina was killed at Parkland. He was worried survivors would take their own lives – just like some of those at Columbine High School did. Thirteen people were murdered in that 1999 shooting in Colorado.
"Your biggest fear materialized when these two students took their own lives?" Bojorquez asked.
"Yeah," Petty said, adding, "We lost 17 beautiful souls on Feb. 14 and… now it's not only 18, it's 19… The way to prevent number 20 is for parents to ask the questions: have you thought about killing yourself? ... If they answer yes to those questions, they're at risk and you need to get help."
Kyra Parrow, Aiello's classmate, believes almost all Stoneman Douglas students remain emotionally and psychologically scarred.
"Looking at Sydney, a lot of us see ourselves," Parrow said, adding, "I always feel like I might be shot, because if it happened to my friends, what makes me think it won't happen to me?"
Aiello's mother, Cara, told CBS Miami station WFOR her daughter had survivor's guilt and post-traumatic stress disorder, but never asked for help. Aiello's close friend, Meadow Pollack, was killed during the shooting.
"I'd just like all these kids to know out there that there's people that care about them and love them, and they should never think that they're alone," said Andrew Pollack, Meadow's father.
This weekend marked the one year anniversary of the March for Our Lives, a massive protest against gun violence organized by the Parkland survivors. Officials said Broward County residents who need help can call 211 and they'll be connected with a therapist.
The National Suicide Prevention Lifeline is also open 24 hours a day for anyone needing help: 1-800-273-8255.
Editor's Note: We've updated this story to remove a reference to a statistic that we have not yet been able to independently verify.