Losing a family member to a natural or accidental cause will undoubtedly cause unbearable suffering.

But these 10 celebrities didn't just have to deal with the loss of their loved ones, they also had to cope with the brutal way in which they were killed.

Some of these celebrities were able to learn who killed their family members, but others were not, and are still haunted by that question today.

1. Charlize Theron

No child should have to witness the death of a parent. It's an experience that would undoubtedly trouble the mind of a kid for the rest of their life.

When Theron was only 15 years old, her abusive alcoholic father was shot by her mother in self defense.

He was in a drunken rage, and Theron's mother had no other choice but to shoot him to protect herself. For that reason, she was never charged for his death.  

The Mad Max actress opened about her father's death, explaining that it wasn't seeing her father die that traumatized her, it was thinking about the times he was alive.

"I think what more affected me for my adult life that happened in my childhood was more the every day living of a child living in the house with an alcoholic and waking up not knowing what was going to happen," she told People.

"And not knowing how my day was going to go and all of it dependent on somebody else and whether he was not going to drink or drink."

2. Jennifer Hudson

The former American Idol contestant and The Voice coach has had her share of ups and downs in life.

In 2008, three of her close family members were murdered.

A year after winning an Oscar for Best Supporting Actress in the movie Dreamgirls, Hudson's mother, brother, and young nephew were murdered by her former brother-in-law, William Balfour.

It's believed that Balfour committed the crime because he was jealous that his estranged wife was dating another man. According to Hudson, he hated when anybody would get close to, or kiss his ex-wife on her cheek, even if they were family.

"None of us wanted her to marry him," Hudson said in court. "We did not like how he treated her."

In 2012, Balfour was found guilty on all counts of murder and sentenced to life in prison.

3. Mark Ruffalo

The Avengers star says the tragic death of his brother, Scott, in late 2008 still affects him today.

"You never get over it; you just get used to it," he told Men's Journal.

Scott, who worked as a hair stylist, was found shot in the head at his LA home, dying days later in a hospital.

Not too long after his death, two people were arrested in connection to the shooting. The first was a woman by the name of Shaha Mishaal Adham and the second was a man named Brian Scofield.

The woman claimed that Scott accidentally shot himself while he was playing Russian Roulette and others claimed that he had a "severe cocaine" addiction.

Now a decade later, this case is still a mystery and no one knows what happened on the day Scott was fatally shot.

4. Bill Cosby

Bill Cosby was recently found guilty on all three counts of sexual indecent assault, which probably makes him one of the most despised celebrity men today.  

But more than two decades ago, Cosby was receiving an outpouring of support after his son, Ennis, was murdered near Interstate 405 in Los Angeles.

Ennis was 27 years old at the time of his death, and was working to receive his doctorate in special education at Columbia University's Teachers College.

While on winter break, he was driving to visit a friend in LA when he got a flat tire, and so he called his friend for help.

When she arrived, she witnessed Ennis getting shot in the head and fled the scene before she risked her life.

Mikhail Markhasev was convicted for the killing and was sentenced to life in prison.

It's believed that the shooter was trying to rob Ennis, but strangely none of his expensive accessories, like his Rolex watch or the money in his pocket, were stolen.

5. Sofia Vergara

The Modern Family star's brother, Rafael, was only 26 years old when he was gunned down in Colombia.

"We come from a successful family, and he knew he was a target for kidnapping," Vergara said, according to Fox News. "He always had bodyguards. Then one day he went out alone and was shot dead. I was devastated."

The crime remains unsolved today, but the family believes there are people who know what happened on that tragic day.

"I've learned that there were witnesses at the scene who were afraid to talk at the time, or may have been blackmailed," private investigator Marcos Rubio told The Enquirer.

There's also rumors that Rafael was having an affair with the girlfriend of a local crime boss, which may be the reason why he ran into trouble.

Two years after her brother's death in 1996, Vergara relocated to Miami. She still hopes her late brother will one day get the justice he deserves.

6. James Ellroy

If you've ever wondered how the writer of LA Confidential and The Black Dahlia comes up with his story ideas, it's likely drawn from his own troubled past.

The crime fiction author's mother, Geneva, was strangled to death and her body was dumped in some bushes by a high school.

Ellroy was only 10 years old at the time of her death, and for years wasn't able to come to grips with this sudden loss.

He suffered with clinical depression for many years and spent his youth drunk and committing petty crimes.

The crime remains unsolved to this day.

7. Serena Williams

Serena and her sister Venus were devastated after their eldest half-sister, Yetunde Price, was shot dead in a drive-by shooting in 2003.

She was only 31 years old and was working as a personal assistant to the tennis stars.

"It was a real dark period in my life. I went through depression. I never even talked about it to my Mom ... No one knew I was in therapy, but I was. I was so close to my sister," Williams told People.

The shooting happened in Compton, a city in Southern LA that's well known for its history of gang violence.

Apparently her boyfriend was the intended victim.

Southside Crips gang member Robert Edward Maxfield was found guilty for the murder three years later, and was sentenced to 15 years in prison.

8. Kelsey Grammer

If this Frasier star isn't the definition of an unfortunate soul, I don't know who is. The funnyman's childhood is literally the opposite of sunshine and rainbows.

When Grammer was just a kid, his parents divorced and he was raised by his mother and grandfather.

When he was 11 years old, his grandfather died, and two years after that, his father, Frank, was murdered.

A mentally unstable man set fire to his father's car, and when Frank went outside to see what was happening, the same man shot him to death.

Almost a decade later, an even greater tragedy befell the actor. His 18-year-old sister, Karen, was raped by four men and murdered.

After that, Grammer's two half-brothers perished in a scuba-diving accident.

In spite of all this tragedy, Grammer has forgiven his sister's killer and found a way to cope with the death of his family members.

"Every one of us is going to experience some terrible loss," he said. "I just got a big dose. For every story you hear that's tragic, there's another that's equally tragic or more so. I think you come to look at it as part of life."

9. Michael Jordan

In 1993, the famous pro basketball player's father, James, was shot dead after pulling up at a rest stop to take a nap in his vehicle.

Two men were reportedly looking for someone to rob, and James happened to be their choice for a victim.

When they realized who they killed they tried to cover their tracks, and so they dumped James's body in a swamp and stole two of Jordan's NBA championship rings.

In the video below, you can see Jordan crying in the locker room while remembering the loss of his father.

10. Roman Polanski

Infamous cult leader Charles Manson is long gone now, but the pain he's inflicted will live on for a very long time.

The French-Polish film director's wife, Sharon Tate, was brutally murdered by Charles Manson's followers in 1969. She was eight months pregnant at the time.  

Polanski was devastated by the murder, and opened up to Spiegel on how long it took for him to cope with this tragedy:

"A long time. Shortly after the murder, I met with a friend, a psychiatrist. He said it would take me at least four years until I could function normally again. Back then, it seemed like a long time to me. But it turned out to be more than four years. I wonder how a psychiatrist can be so wrong."

It's awful that his pregnant wife died, but it doesn't excuse the director's actions a decade later, when he was charged for raping a 13-year-old girl.

If you liked this article, check out 10 movies based on true stories and the tragic details they left out.