Newark, NJ - City officials are bracing for throngs of mourners, celebrities and the media for Saturday's funeral of Whitney Houston.

A Friday viewing at Whigham Funeral Home here was scheduled for members of the 48-year-old pop star's family. A row of curtains outside the building's entrances blocked anyone seen arriving.

While Houston's family has tried to keep the fallout of Houston's death a private affair, media interest remains intense. A growing swell of reporters and photographers was camped outside the funeral home and Newark's New Hope Baptist Church, where Newark police are cordoning off a six square-block area to keep crowds and media at bay.

Newark Police are providing escorts to the celebrities expected at Saturday's invitation-only service for 1,500, including Oprah Winfrey, Elton John, Bill Cosby, Aretha Franklin, Stevie Wonder and Beyoncé. Music producer Clive Davis and actor Kevin Costner, Houston's co-star in her debut 1992 film The Bodyguard, are expected to speak at the service for the pop diva, who died Saturday in her Beverly Hills hotel room on the eve of the Grammy Awards. The cause of death is not expected to be determined for several weeks.

Outside the front entrance of the funeral home early Friday, people were snapping photos of a make-shift memorial that included flowers, candles, handwritten signs and balloons with phrases such as "I miss you" and "I love you."

Inside the entry doors was a large poster of a smiling Houston, and to the left, a long black evening dress and a pair of gold and black high-heel shoes. As Houston's music played, well-wishers lined up to write notes in a book left on a stand outside labeled "friends and relatives."

Jerry Clark, who stopped by Friday morning, says he plans to stake out a spot outside the church early Saturday. "I know it's going to be be packed,'' says Clark, 49, who knew Houston from her early years growing up in the city.

Scores of brightly colored balloons, bouquets of flowers and handwritten signs of sympathy were already outside the church Friday. So were photographers, manning a nearby rooftop. And on a nearby block, one entrepreneur set up a stand, selling single, long-stem roses for $5 and small stuffed teddy bears for $2.

Betty Grier came by the funeral home to pay her respects before picking up her 10-year-old granddaughter, Nia Phoenix, who attends the Whitney Houston Academy of Creative and Performing Arts in nearby East Orange. Students there contributed candles and flowers to an informal memorial that sprang up in front of the school. Grier says she cried when she heard a Houston song this week.

Ramona Kelly was also outside the funeral home Friday. "She inspires me," says Kelly, 28, who sang Houston's One Moment In Time at the New Hope Church when she graduated high school.

While some observers say there should be a more public service honoring Houston, Kelly says she understood the Houston family's preferences for a privacy. "They shared her with the world her whole life,'' Kelly says.

Houston will be buried next to her father, John Russell Houston Jr., at the Fairview Cemetery in nearby Westfield.

Newark Mayor Cory Booker said the city would lower flags to half-staff Friday and Saturday to honor Houston. "Our city is mourning the loss of one of its native daughters and one of music's shining stars,'' Booker said.

But New Jersey Gov. Chris Christie's decision to order state flags flown at half-staff drew criticism because of Houston's history of alcohol and drug abuse.

Nearly 13,000 USA TODAY readers weighed in at Lifeline Live, and 77% said in an informal poll that flags flying at half-staff for Houston was "inappropriate."

Christie, a Republican, was defended by conservative radio talk show host Rush Limbaugh, who noted that flags were lowered after last year's death of Clarence Clemons, a long-time member of Bruce Springsteen's E Street Band.

Christie said Houston's substance abuse history did not diminish "the good things she did in her life."

The Asbury Park Press reported Christie has ordered flags to be lowered 43 times since taking office as governor in January 2010. The overwhelming majority of those instances — 30 — were for servicemembers from New Jersey killed in action.