The three-year-old boy caught up in a tragic domestic stabbing incident in Oshawa this past weekend has died in hospital.

Nathan Kelly died Wednesday at the Hospital for Sick Children from injuries he suffered after being stabbed at a birthday party for brother Brandon, 11, at the family's home on Nov. 29.

The toddler's mother, Lesley Kelly, also died from wounds suffered during the attack, but survived long enough to call 911. Family and police say she died trying to shield her husband and children from the attack.

Rick Kelly, Nathan's 29-year-old father, and brother Riley, 5, were both injured. They are recovering in hospital and are expected to survive.

The suspect, 47-year-old Gino Petralia, showed up at the party. His son Steven, 13 and Rick's half-brother, had been taken in by the Kellys after the boy's mother died this past summer. Rick asked Petralia to leave, which may have triggered the attack. Steven wasn't injured in the outburst of violence.

Police later shot Petralia dead during a confrontation at an adjacent townhouse unit. Petralia had previous involvement with the law.

The Kellys hope "to help other children by consenting to organ donation, something that ... Nathan's mother would have wanted," Durham police said in a news release issued on behalf of the family.

The family also thanked the many friends, neighbours and strangers who offered their "love and support throughout this most difficult time."

Private funeral arrangements will be made for both victims.

Two trust funds have been set up in support of the Kelly family.

Donations to the "Kelly Family Trust" can be made at any CIBC Branch via Account # 00892/03-22938 or through any TD Canada Trust branch via Transit #3184 Account: # 6322034.

Kelly's death marks Durham Region's fifth homicide for 2008.