TODAY | April 27, 2013
>>> we do begin this half hour with a tragic, wrong way accident on the new york highway. you may remember the story. it is heart breaking. a mother driving drunk and high kills herself, a daughter, three nieces, three men in another car. now her sister-in-law is telling her story in a new book called "i'll see you again." in an interview that first aired on rock center we talked with her and her husband warren to talk about the accident and how they're now finding a reason to hope.
>> love your children. cherish your children. kiss your children. and don't ever forget.
>> reporter: jackie and warren had just buried their three beautiful girls .
>> i love you all.
>> reporter: they were 8-year-old emma.
>> make a silly face.
>> reporter: 7-year-old allison.
>> reporter: and 5-year-old katy.
>> i did it, daddy!
>> reporter: and they were trying to cope with their heart breaking new reality -- life without their daughters. jackie slid beyond despair.
>> they were really just really amazing girls. and i don't know. it changed everything.
>> reporter: she says she became detached from reality. her close friends , melissa, isabelle, and janine, stayed near jackie around the clock, making meals, even sleeping outside her door for months.
>> she'd call out in the middle of the night . are the girls there? where are the girls? do you have them at your house? then you have to go through the process again. no, sweetheart. show her the papers or explain to her.
>> reporter: the grief took a toll on jackie and warren's marriage as well.
>> in the book you talk about the really huge arguments with your husband, so raw and so emotional. and, yet, you two held on to each other as much as you fought.
>> yes. you know, he's a really strong person. i love him. i'm sorry for him.
>> reporter: you're sorry for his suffering you mean?
>> yes. i would do anything not to see him in pain.
>> reporter: jackie and warren realized they were stronger together and knew they had to lean on each other if they were going to survive. after a while, jackie 's friends suggested that she have another baby to help her heal and to start living again. initially she refused to even consider the idea. but eventually, jackie opened up to the possibility. and 16 months after the accident, she became pregnant. on october 11th , 2011 , casey rose arrived. jackie says that casey has brought her back to life. and with the arrival of baby casey came something else. a need for jackie to reconcile her feelings about diane . one day standing by her daughters' graves, right next to diane 's, she realized she couldn't love her new baby and hate diane at the same time. so for the first time you turned and walked toward diane 's grave. so you reached out and touched her headstone and what did you say?
>> i just said, i don't understand. i don't know what happened that day. and i always loved you and i forgive you. i still love her. up until that day, i only knew what i knew, and she was a good person and a good mom and a good, you know, friend, so i don't know what happened that day. i really don't.
>> reporter: and even not knowing, you're able to forgive her?
>> i had to. i had no choice. because it was -- i wouldn't have been able to live the other way.
>> powerful story.