LOS ANGELES (CNN) -- Michael Jackson often cried after talking to AEG Live executives as he prepared for his comeback concerts, his oldest son testified Wednesday.
"After he got off the phone, he would cry," Prince Jackson testified. "He would say 'They're going to kill me, they're going to kill me.'"
His father told him he was talking about AEG Live CEO Randy Phillips and his ex-manager, Dr. Tohme Tohme, Prince said.
Prince, 16, began his testimony Wednesday morning in his family's wrongful death lawsuit against Jackson's last concert promoter, AEG Live.
His first 30 minutes on the stand were filled with videos and photographs of Jackson with his children, but then the questioning by Jackson lawyer Brian Panish focused on the last weeks of his father's life.
Prince testified that Phillips visited Jackson's rented Los Angeles mansion and spoke aggressively to Dr. Conrad Murray the night before his father's death.
"He was grabbing his elbow," Prince said. "It looked aggressive to me. He was grabbing by the back of his elbow and they were really close and he was making hand motions."
He couldn't hear what Phillips was saying to Murray, he said.
Michael Jackson was not there because he was at his last rehearsal, Prince said. He called his father from the security guard shack telephone to let him know Phillips was there. His father asked him to offer Phillips food and drink.
Prince said that was his last conversation with his father.
Prince was 12 when the pop icon died, but he said his father confided in him about whom he trusted and didn't trust and what he feared as he prepared for his comeback concerts.
Michael Jackson's three children -- Prince, Paris and Blanket -- and their grandmother Katherine Jackson are plaintiffs in the lawsuit, which contends AEG Live is liable in Jackson's death because the company hired, retained or supervised Murray, the doctor convicted of involuntary manslaughter.
Murray told investigators he gave Jackson nightly infusions of the surgical anesthetic propofol to treat his insomnia. The coroner ruled the singer died of an overdose of the drug.
AEG Live executives allegedly created a medical conflict of interest that pressured Murray to pursue the dangerous treatments so Jackson would be rested for rehearsals, while ignoring warning signs that his health was failing, Jackson family lawyers argue.
AEG Live lawyers contend that it was Jackson who chose and controlled the doctor and that company executives had no way of knowing what treatments Murray was delivering.
AEG Live lead lawyer Marvin Putnam's cross-examination of Prince lasted just 25 minutes. It centered on trying to discredit his testimony about Phillips' visit to his home and about cash payments that Prince said his father gave Murray at times.
Prince stood by his story about the Phillips and Murray encounter, although he conceded it could have been two nights before his father's death and not the last night.
The toll of losing their father
Prince's testimony gave Jackson lawyers a chance to show jurors the emotional toll suffered by Jackson's children, which they would have to put a dollar figure on if they conclude AEG Live is liable in their father's death.
"I can't sleep at night," Prince said. "I have a hard time sleeping." The death left him "emotionally distant from a lot of people" for a while, he said.
He's missed sharing with his father "the first day of going to school, having the first girlfriend, being able to drive," Prince testified.
While Paris Jackson's suicide attempt and hospitalization was not brought up in court -- and it is unclear if jurors learned about it in the news -- Prince did speak about his sister.
"I think out of all of my siblings she was probably hit the hardest because she was my dad's princess," he said.
Prince said the questioning of Paris by AEG Live lawyers over two days in March was painful for her. "She had some problems before, after and, I assume, during," he said.
"She definitely is dealing with it in her own way," her brother said.
Paris, who was 11 when her father died, is not available to testify in person in court because she is hospitalized for psychiatric treatment.
While he and his sister no longer want to celebrate birthdays because "it's not the same without" their father, Blanket, now 11, does, Prince said.
"Right now, I don't know if Blanket realizes what he lost," he said. "He was so young. He is still growing up just like I am and he doesn't have a father to guide him."
AEG Live attempted to compel Blanket, the youngest child, to testify, but the judge rejected its request after a psychologist said it would harm the boy.
Changing the world?
Jurors watched a home video of Michael Jackson questioning his three children about how they planned "to change the world" when they grow up.
Prince testified that the video was made at Christmas.
"What's Christmas mean?" Jackson is heard asking his
"Love," Blanket responded.
"Who's Blanket going to be to change this world?" Jackson asked.
"I don't know," Blanket, who appeared to be about 5 at the time, answered.
"What does Paris want to do? Be honest search your heart," Jackson said.
"Help the poor," she answered. Paris also said she would like to be a gymnast.
Prince told his father he aspired to be a movie director and architect because he liked "making things."
"Daddy's little man"
Jackson confided in his oldest son about his business dealings at an early age.
"Prince has always been, even at 12, the little man -- Daddy's little man," Jackson chef Kai Chase testified. "He wanted his father to be very proud of him, which Michael was."
"The weight of the world is on his shoulders, the eldest, big brother and father figure to his siblings," Chase testified. "It's a lot for him, growing, liking girls. He wishes his father was here to give him advice. It's devastating to him."
Prince recently began pursuing an entertainment career, working several days as a "special correspondent" for "Entertainment Tonight" and acting in an episode of the television show "90210."
The trial is in its ninth week and is expected to last until August.