The investigation continues after three children and three adults were killed in a school shooting in Nashville, Tennessee.Now, parents across the country will be having tough conversations with their kids about this tragedy.Previous Coverage: Nashville school shooting: What we know and don't knowTerry Lyles is a Wellington-based psychologist who has been helping people cope with stress for 25 years.He said communication and preparation are key for families after tragedies like this, to turn bad stress into good stress.He said it’s important for parents to listen to their children and talk to them about any fears and concerns they might have after hearing about violence in schools.He also encourages parents to challenge their children to be able to respond to a potentially violent situation and respond correctly.That means preparing and having a plan in place, like having a code word.“When you text or you call in this code, you don't have to say a word; we know there's something wrong, and we're coming towards you. That gives the child or individual student a level of security, it gives the parent a level of security over and above the physical security that's taking place at the school in this case,” Lyles said.He says it’s also important to rehearse and go through that plan several times so kids can just react in emergency situations instead of wasting precious minutes trying to think of what to do.And ultimately, that preparedness will give families some peace of mind."The way you create your own luck, so to speak, which is opportunity, you know, meeting us head-on preparation is we have to prepare. Prepare your students, prepare your household, prepare your community, and when everybody works together, look, we're never going to eliminate these shootings. It's just what it is. People are people. Things happen. And it could happen in any neighborhood, in any city or state across the country. But preparedness is the key to potential success and safety,” Lyles said.Lyles' manual, Caught in the Crossfire, detailing how to achieve emotional recovery and stress relief after gunfire can be found here.