HARTFORD, Conn. (AP) - A Connecticut appeals court has heard arguments over whether Sandy Hook Elementary School officials were negligent in failing to order a lockdown before a gunman killed 20 first-graders and six educators in 2012.

A lawyer for the parents of two children killed in the massacre told the state Appellate Court on Wednesday that school officials didn't follow protocols and order a lockdown that may have saved lives when they heard the gunman shoot his way through the school's locked entrance.

The parents are appealing a lower court ruling that dismissed their lawsuit against the town and its schools.

The town's lawyer argued officials weren't certain what they heard was gunfire in the chaotic first seconds and ordering a lockdown was discretionary.

It's not clear when the Appellate Court will rule.