Parents should give children the opportunity to speak about the incident if they come home from school and start talking about it.
"We want them to talk about it," said Veronica Chavez, a clinical psychologist and specialist in childhood trauma at Children's Hospital Los Angeles.
Parents should reassure their children and explain that they will be safe at school and there are people there who will protect them.
Discussions should be age-appropriate and the younger the child, the simpler it should be, Chavez said.
"Sit down with them and talk with them but don't give them too much information. Only give them the basics," Chavez said.
Although the shooting can be traumatic for anybody, children are especially vulnerable, said psychiatrist Dr. Moe Gelbart.
"Kids are going to hear things from all over," said Gelbart, the executive director of the Thelma McMillen Center for Outpatient Chemical Dependency at Torrance Memorial Medical Center. "There's info that you don't know that's coming in."
Gelbart said that parents should not whitewash the tragedy, but should be careful to discuss the events in a way that is appropriate to the child's age.
"You have to allow the children to set the pace," he said. "If they're asking you, you have to be honest, but within what they can cope with and understand."
Children older than 11 or 12 are better equipped to deal with harsh realities, Gelbart said. Children younger than that may need to be guided in the discussion.
"Little kids can't talk about their feelings," he said. "It's up to the parents to figure out what the children are feeling and validate those feelings. If a kid says, `Mommy, what happened in school?' If they ask a question, answer it in terms they can understand. If they say they're scared or anxious, say you understand that. But give them reassuring words."
Parents should also keep an eye out for changes in a child's behavior - things like nightmares, fear of going to school or not sleeping.
"Talk to your children and try to calm their fears," Gelbart said. "They have to be told the truth. Bad things happen, but not everybody is bad. The child needs to feel the world is safe for them, their parents are there for them."
Parents should look for signs such as difficulty sleeping, nightmares, bed wetting, aggression and nervousness.
Smaller children may experience regressive behavior or may lash out at younger siblings or classmates.
Older children may have difficulty sleeping or concentrating.
But, experts say, if a child hasn't brought up the subject, don't raise the issue.
"As a parent, you don't want to bring up something they won't be aware of," Chavez said. "If kids do bring it up, that's when you should talk about it."
At home, parents should be on the lookout for verbal and non-verbal cues that children are stressed by an event such as Friday's school shooting.
Children should know that schools prepare to prevent such incidents through training, security and other means, said Ailleth Tom, coordinator for crisis counseling and intervention services with the School Mental Health Department of the Los Angeles Unified School District.
"Schools are still the safest places for a child to be at," Tom said.
The shooting has attracted significant media attention so parents should also limit their children's television viewing and access to the Internet as much as possible.
Watching the incident repeatedly can create problems for children.
After the Sept. 11 attacks on the East Coast, some children had what is referred to as vicarious trauma. Many children repeatedly watched coverage of the attacks and their aftermath on television and created trauma in them, Chavez said.
Parents who see a change in behavior in their children may want to talk to school counselors or seek the assistance of mental health professionals to help the child work through the stress an incident such as this one can bring on.
Staff writers Monica Rodriguez and Josh Greenberg as well as the Contra Costa Times contributed to this report.