Singer Demi Lovato has thanked fans for their support and well wishes following the death of her father. The pop star's sister Dallas revealed in a post on Twitter.com on Saturday (22Jun13) that their dad, Patrick Lovato, had passed away. Lovato, who has been estranged from her dad since 2007, pulled out of an appearance at a publicity event for America's The X Factor on Saturday, and she has now broken her silence. In a post on her Twitter page, she writes, "I feel so humbled to have had so much support from my fans, friends, family and complete strangers... God bless you all, thank you so much." Patrick Lovato, 53, a former country singer and studio engineer, is said to have been battling cancer in recent years, but no further details about his death have been made available.