ST. AUGUSTINE, Fla. -- A St. Johns County grand jury indicted a 51-year-old woman on two counts of manslaughter and other charges, believing she allowed alcohol and drugs at a party two teens were leaving when they died in a fiery single-vehicle wreck in January.

Jessy Pitts, 18, and 17-year-old Taylor Brennan, a Bartram Trail High School senior, were killed early the morning of Jan. 12 when a Ford Thunderbird hit a guardrail along state Road 13 and went into a stand of trees before catching fire.

The victims were so badly burned that dental records were used to identify them.

The final accident report found that the Pitts' blood alcohol content was .18 -- twice the legal limit -- and he also had marijuana in his system. Brennan also had marijuana in her system and her BAC was measured at .097.

In addition to two counts of manslaughter -- second-degree felonies -- Diane Katz Santarelli was also charged with one count of contributing to the delinquency of a minor and four counts of holding an open house party.

"Santarelli's actions led directly to the deaths ... when Pitts lost control of his vehicle shortly after leaving Santarelli's residence, according to the charging affidavit.

Investigators said Santarelli hosted at least four house parties between Sept. 26, 2008 and Jan. 12, 2009 and allowed minors to consume alcohol to excess as well as use marijuana and nitrous oxide. According to the indictment, she was present during the parties and even participated in the illegal activies.

"Sometimes we just think nothing's going to happen to us," Lt. Bill Leeper of the Florida Highway Patrol said. "This is something that should not have happened. Those two people should not be dead."