( CNN ) -- When our father , Michael Grant Cahill , was murdered in the Fort Hood , Texas , shooting on November 5 , 2009 , we were barraged with the question , `` What can we do ? '' People wanted to help , get milk , make us casserole and assist relatives with travel . Support was everywhere . That support remains . In the wake of shootings in Newtown , Aurora , Tucson , Oak Creek , and too many more places , people are asking again , `` What can we do ? '' First , we must stop asking `` why ? '' and start asking `` why not ? '' In other words , what are we doing to prevent these tragic shootings ? Opinion : Patterns and warning signs . These events are caused by a perfect storm of issues . These include the proliferation of assault rifles and clips of 30 to 100 rounds , access to mental health support or lack of it , and , most important , falling short in our efforts of prevention . It is a sinking ship , and we must start filling the holes . Holes made by guns that shoot 45 rounds in 1 minute , like the semi-automatic rifle used in Newtown . Holes inspired by the glorification of the shooters in previous shootings . Their life-size faces on the cover of Time magazine , bought by you , and dominating the Internet sites you browse , while the fallen are left in the photo albums of their families . Holes made by the lack of help and understanding in our country 's mental health . Holes made by the fact that the Newtown children are not the only children we have lost to mass shootings . They are the unfortunate 20 who made us realize the water is up to our throats . The water is rising . What hole can you fill ? Can you think about prevention rather than reaction by supporting programs in our schools that encourage our children to look out for one another ? Can you be honest about what it would take to defend yourself against an assault rifle ? Can you pay attention to important legislation and contact your congressman and senators to show support or share your thoughts ? Can you stop saying , `` Glad it was n't me '' and start saying `` What if it was me ? '' We can not continue accepting that `` these things happen '' and `` you will never stop evil . '' Those statements ensure that more innocents will die . Our father charged a gun outfitted with 30-round extended clips and was shot six times . Dad never let evil get the last word . He never looked at a problem and thought it was hopeless . We must do the same , and we must be honest : sacrificing our pride and admitting that we , as a nation , have a problem . We need training for our teachers and police officers . Training that does n't just focus on how to react to shootings but knows the community and makes relationships that lead to safer communities . Opinion : Freedom Group , a gunmaker ripe for an ethical takeover . Programs such as Rachel 's Challenge started after the Columbine shooting by the parents of the first student killed , Rachel Joy Scott . The Memorial Institute for the Prevention of Terrorism , started after the Oklahoma City Bombing , which trains police officers not just to recognize danger but how to create communities that are more aware . `` Random actor '' trainings , by Dan Korem , teaching educators how to identify possible mass shooters , focus on at-risk kids and help those students . Gun sales are rising , but is the support for the families affected by some of those guns and commitment to prevention rising with it ? Here is the question we are haunted by : `` What is wrong with us that it takes 20 children dying in one shooting to make us change ? '' And some of us still wo n't . We have to address the answers , and we have to have the conversation . Let 's start fixing the problem instead of treating the symptoms . The opinions expressed in this commentary are solely those of the authors .
Cahill and Vanacker : Our father was murdered in the Fort Hood shooting in 2009 . They ask : What are we doing to prevent these tragic shootings ? We need training for our teachers and police officers , they say . They ask : Gun sales are rising , but is commitment to prevention rising with it ?