MIAMI -- What happens today in a Miami courtroom could have a huge impact on thousands of children with autism.

A group of Miami attorneys is fighting for the right to prove in court that many autistic children were poisoned by Mercury. Many parents and a growing number of researchers believe that Mercury came from vaccines.

Some local parents are waiting anxiously for the outcome of the hearing.

From the day Aaron Blackburn was born, his proud parents recorded his milestones, and everything seemed perfect. It was that way for David Bennett's family, too.

As a toddler, David was full of personality. His mother Hilda says, "David was a very playful baby. He would seek out others to make eyes at them and to flirt. He loved blondes!"

But by the age of two something changed dramatically. Both boys stopped communicating. Their diagnosis: Autism.

Hilda says, "It was like he became deaf and unresponsive in many ways."

Both families say their boys crashed after getting their routine vaccinations.

Ellen, Aaron's mother says, "He just got this high fever. He just looked like somebody just stole him right out of his body.

Before the 1990's, one in 10,000 children was diagnosed with autism. Recent studies show it's at least 1 in 500 kids now.

Attorneys across the country want to prove that kids like David were poisoned by Thimerosal, a compound that contains the toxic heavy metal Mercury that is found in vaccines.

Attorney Elwood Lippincott says, "As the cumulative mercury exposure increased with the addition of additional vaccines to the required schedule, more kids became autistic.

Autism and mercury poisoning have many of the same symptoms: loss of speech and obsessive compulsive behavior that has many researchers theorizing there is a link between vaccines and the mercury in them and the increase in autism.

Hilda Bennett says, "Mercury is dangerous to pregnant women. The CDC is telling women not to eat too much tuna, but my son had 25 shots with Thimerosal before he was 15 months old."

Because of these concerns, vaccines made after 2000 no longer contain Thimerosal. Still, many pediatricians say there is no scientific proof of a link.

Dr. Lee Sanders, a University of Miami Pediatrician, said, "The institute of Medicine and American Academy of Pediatrics can find no conclusive link between vaccines and serious neurological or developmental problems."

But parents want a jury to hear both sides and decide whether drug companies should be held accountable for using mercury in vaccines.

Mercury has been removed from latex paint by the federal government, from eye drops, over-the-counter medications, batteries and even dog vaccines, but to this day, the FDA has never banned Mercury from childhood vaccines.

This report is not anti-vaccine, every one agrees how important vaccines are to public health. The focus of the lawsuit is on the possible link between Thimerosal and autism.

The bottom line for parents: drug companies have voluntarily taken the mercury compound out of the vaccines, but nothing was recalled. You can talk to your pediatrician and make sure that your child's inoculation does not contain Mercury.

For more information, read the FDA's FAQ on Thimerosal and vaccinations.