Late last night, Whitney Houston’s 18-year-old daughter Bobbi Kristina Brown was rushed to an L.A. hospital, hours after her mother was found dead, “partially submerged in the bathtub†of room 434 in the Beverly Hilton. “[Kristina] was having a complete breakdown,†a source told People magazine. Just days ago she and her mother had been seen happy, healthy, and beautiful, frolicking in the Beverly Hilton’s pool, according to an unnamed music exec and hotel guest who spoke with CNN. Last night and all day today, tributes have been rolling in from across a grief-stricken music industry (Entertainment Weekly and the Times’ ArtsBeat blog have rounded up a few dozen here), but none comes close to the rawness of a daughter’s frantic disbelief, or of Houston’s ex-husband Bobby Brown’s tearful farewell at a performance last night: “I love you, Whitney.†[People]