HOUSTON -

Drivers are becoming intoxicated without taking a drink and are causing collisions that are destroying innocent lives.

The head on-crash was violent and horrific. It happened on a stretch of Highway 105 in East Montgomery County when Sherri Holloway's SUV crossed over the road's center line and smashed into a van. The impact killed 34-year-old Kenneth Buffington.

Investigators said it all happened because Holloway was intoxicated.

"She got her pills, and then she started popping them," said Warren Diepraam, an assistant district attorney in Montgomery County. "Then, she drove and she killed somebody."

Holloway wasn't drunk on alcohol or high on illegal drugs. Instead, investigators, said she was intoxicated by using prescription pills.

"Intoxication is intoxication, no matter what substance causes it," said Diepraam.

Diapraam said Holloway's wreck highlights an alarming wave hitting Houston-area highways -- drivers hooked on prescription pills get behind the wheel and someone ends up dead. Diapraam cited two recent hospital studies show that twice as many car accident victims said they were under the influence of prescription pills than alcohol. In just two years, there's been an almost 20 percent increase in DWI blood tests coming back positive for prescription drugs.

In Montgomery County, the numbers are even more shocking.

"Almost 50 percent of our fatal crashes involve these sorts of drug," said Diepraam.

Many users are getting their fix from small pill clinics peppered across Southeast Texas. Local 2 hidden cameras have shown how easy it is to walk into a Houston-area pill clinic and walk out with hundreds of pills.

The most popular prescription is a combination of Soma, Xanax and Hydrocodone. It's the same combination showing up in many of those DWI blood tests.

"At one point, I even remember forgetting I was driving," said Scott Lynch, a former prescription pill user who lives in Austin.

Lynch said he used to take 10 Xanax pills in a day then drive his car. He ended up crashing his car in Austin and going to prison.

"For the most part, it was pretty much a blackout," said Lynch, who now helps other users overcome their addiction to prescription drugs. "I remember bits and pieces of trying to drive home. I can't even remember the wreck to be honest."

"They're not just slightly impaired," said Diepraam. "They are falling down drunk as a general rule."

Unlike drunken driving crashes that mostly happen late at night, "drugged" drivers are on the road in the middle of the day or on your morning commute.

"Pretty much every crash we've seen has been during regular work time hours," Diepraam said. "These people do it when everybody is on the road."

That's exactly when Holloway's pill addiction turned into tragedy. Her accident happened around 2 p.m. on a weekday afternoon.

A jury convicted Holloway of intoxication manslaughter. She was sentenced to 12 years in prison.