There is an effort in the form of a petition to prevent a future tragedy after Tava Woodard a Johnson City convenience store clerk was shot and killed.A petition now has more than 600 signatures calling for Tava Woodard’s employer to install panic buttons at all its convenience stores, allowing clerks to call for police.“That convenience store is not far from the Johnson City Police Department,” said Brennan Ricker, who once worked with Woodard’s mother. “The end result could have very well been the same, but at least she could have had a fighting chance.”