A South Bay family says they're feeling pain and disbelief after their sister was killed by her estranged husband right in front of her children. Police say Erica Chanon Hernandez was killed by her estranged husband at her North San Jose apartment early Sunday morning. Police say the husband then killed a security guard who came to help before turning the gun on himself. "We still can't believe what happened," said Erica's sister, Maria Isabel Chanon. "This morning, I was going to call my sister and I'm going to tell her, 'Hey, let's go do this,' but then I realized that she’s no longer with us." Maria and her sister, Georgina Chanon, said Erica was a loving mother of six – ranging in age from 1 to 10 years old – who worked long hours to provide for her children. The sisters said Erica's estranged husband was abusive and should have been locked up a long time ago, adding that the system failed her.