There has been much speculation about Jenni Rivera's untimely death.

What is know is that she died in a plane crash. Everything from the age of the plane to the age of the pilot came into question after her death. There were also sources that said Rivera's death was no accident. A video of her in concert supports this theory.

During a performance of "Paloma Negra" posted onto a YouTube, it sounds as though a man says: "Today, they kill her." The sound can be heard at around the 2:20 mark.

It's not entirely clear, but YouTube viewers noticed these words. However, some people have also chimed in with possible alternate variations. One said, the person actually says, "Vamos grandota," which would roughly translate to "Let's go, big one." Another thinks it's "animo hermosa," which means "High spirits, gorgeous."

But other YouTube users are certain they hear the message of warning.

One said, "Omg noo!! It does say that on 2:20."

There are a lot of answered questions about her death. A simple Google search will show that people have all sorts of theories.

In a Daily News article, it was revealed that Jenni Rivera performed for a drug cartel, according to a lawyer. He claimed that she did drugs and performed for many of the drug gang's parties.

These claims were made in 2009, which is the same year that Rivera was held at the Mexico City airport. She was carrying more than $50,000 in cash. She had only claimed $20,000.

Rivera denied being tied to any cartel.

"Yes, it is true that at times you are not aware of who contracts you [for a show]," she said. "They tell you that you will sing at a certain place and that they will pay you a certain amount of money."

There was also one message sent to the singer over Twitter on June 2010 that clearly threatened her. 

Listen to the video below. What do you hear?