Josh Henderson suffered a double blow when his TV dad Larry Hagman died - the young actor is also in mourning for his grandmother.

The TV icon, who played backstabbing oil baron J.R. Ewing in the original version of the soap opera and the current revamp, passed away at a hospital in Texas on Friday (23Nov12) after suffering complications from his battle with cancer.

Henderson, who plays J.R.'s son John Ross Ewing III, paid his respects to his onscreen father on Twitter.com on Monday night (26Nov12), hailing him as a "mentor and a friend", and he also thanked fans for their well wishes following the death of his grandmother, who passed away earlier this month (Nov12).

In a post, he writes, "Sorry I have been somewhat missing lately. Been a rough last few weeks. Can't thank y'all enough for the love and prayers. Means the world."

Henderson had previously uploaded a photograph of a coffin adorned with flowers alongside the message, "Till we meet in Heaven.. Love you grandma."