DANVILLE — Almost 10 years to the day after their 10-year-old son, Troy, and 7-year-old daughter, Alana, were killed by an intoxicated driver, Danville residents Bob and Carmen Pack led a gathering of friends, family, and well-wishers to honor the memory of their children and to advocate for legislative changes that they hope will prevent similar tragedies.

Specifically, the couple is working to get enough signatures for the Troy and Alana Pack Patient Safety Act, a measure they hope to get on the November 2014 ballot, which would require doctors submit to random drug testing. It would also adjust the amount of money that families of victims of medical malpractice can be awarded under California law, which was set at $250,000 in 1975, but hasn't been adjusted for inflation since.

"Working on these efforts helps me heal," Bob Pack said. "It's something I believe in, and I can't do it for my two children, but I can do it for other children."

There was a somber mood during the memorial, but occasional outpourings of joy as well. When Pack introduced his and Carmen's 7-year-old daughter, Noelle, to the crowd as a sign of his hope for the future, the child gleefully jumped around her mother for an impromptu dance in front of news cameras, and the crowd burst into laughter.

The memorial culminated with a release of butterflies and balloons to honor Troy and Alana's memory. There were also brief speeches from the Packs, as well as Contra Costa Supervisor Candace Andersen, who was the mayor of Danville when the accident occurred, and state Sen. Mark DeSaulnier, D-Concord, who has worked closely with the Pack family over the years.

"Although I didn't know Troy and Alana, I think in a very meaningful way, I came to know them," DeSaulnier said. "Clearly … their spirit is here today."