LOS ANGELES -- Michael Jackson's mother tearfully described finding out about her son's death Friday and said she expressed concerns about his comeback concert schedule to the promoters of the tour.

Katherine Jackson said she called the CEO of promoter AEG Live LLC to express her view that her son could have done 50 shows, but not if they were spaced closely together.

"He couldn't do every other night like AEG wanted him to do at first," Katherine Jackson said.

She said she called AEG Live CEO Randy Phillips and her son's manager, Tohme Tohme, to express her concerns about the "This Is It" schedule.

She didn't describe any additional details about the calls. Katherine Jackson is expected to be the final plaintiff's witness in her case against AEG Live, which has lasted 12 weeks. The defence case is scheduled to begin next week.

Katherine Jackson has been a courtroom fixture during the civil trial, sitting in the front row as witnesses described her son's creativity and interactions with AEG Live executives.

The Jackson family matriarch sued AEG Live in 2010 for negligence, claiming it failed to adequately investigate the doctor who was later convicted of involuntary manslaughter for giving the singer an overdose of anesthetic in 2009.

AEG denies it hired the doctor or bears any responsibility for the singer's death.

She said she also heard from her other children that Michael Jackson was abusing prescription medication, but she didn't know what to believe. She said she visited him in Las Vegas a few years ago to ask him about it.

"He promised, he kept saying, 'I'm OK,"' she told the jury.

"Sometimes the mothers are the last to know," she said.

She said she told her son, "I don't want to hear on the news that you're not here anymore."

Katherine Jackson did not say when the meeting with her son occurred.

Under questioning by AEG Live defence attorney Marvin S. Putnam, she said it had been difficult to see and hear unflattering descriptions of her son.

"It hurts to sit here and listen to all these things," Katherine Jackson said. "To listen to how sick my son was and nobody was trying to help him."

She said an email written by Paul Gongaware, a top AEG Live executive, that described her son as lazy was especially hurtful.

"My son is not lazy. You don't get to be the biggest," she said, pausing, "by being lazy."

She broke down as she described the day her son died. She said she was told by another of her son's managers, Frank Dileo. "I just started screaming," she said, crying and clutching a tissue in one of her hands.

Katherine Jackson said her granddaughter Paris Jackson was inconsolable at the hospital and was looking skyward saying, "'I can't live without you"' and "'I'm going with you."'

Her attorney, Brian Panish, concluded his questioning by playing a montage of clips of Jackson's children while music of his song "Speechless" played.

Putnam asked her about her decision to sue AEG Live in September 2010. She said she didn't discuss with her children or her grandchildren before filing the lawsuit.

"This was your decision alone," Putnam asked.

She said it was.