it s one of the busiest trauma centers in the nation. you have your blade? okay, perfect. reporter: and cnn got exclusive access inside as pediatric trauma medical director and her team demonstrated preparations for a mass casualty event. anesthesia is here. go ahead and get up there with kelly so we can back her up in case it becomes a difficult airway. reporter: today it s a drill. this is one of the teams we formed, and the day of the mass casualty event, we formed multiple teams such as this. reporter: but it wasn t a drill on tuesday when a teenaged gunman burst inside robb elementary school in uvalde, texas, murdering 19 children and two teachers, injuring at least 17 others, officials say. it s devastating. i think the same thing that every other person in this country is thinking, you know, how horrible their last moments were, right, and what that scene
case it becomes a difficult air way. reporter: today, it is a drill. this is one of the teams that we formed. and the day of the mass casualty event we formed multiple teams such as this. reporter: but it wasn t a drill on tuesday. when a teenage gunman burst inside robb elementary school in uvalde, texas. murdering 19 children and two teachers, injuring at least 17 others, officials say. it is devastating. i think the same thing that every other person in this country is thinking, you know, how horrible their last moments were, right, and what that scene looks like. reporter: the trauma unit prepared to receive dozens of uvalde s wounded. nurse colleen davis recalled the agonizing wait for patients and a grim realization. after a while you start realizing more aren t coming and you start realizing why and then the weight of that sets in and it stays with you for the rest
demonstrated preparations for a mass casualty event. anesthesia is here. go ahead, get up there with kelly so we can back her up in case it becomes a difficult airway. reporter: this is a drill. this is one of the teams that we formed on the day of the mass casualty event. we formed multiple teams such as this. reporter: but it wasn t a drill on tuesday when the teenage gunman in robb elementary in uvalde, texas, murdering 19 children and two teachers, injuring at least 17 others officials say. it s devastating. i think the same thing that every other person in this country is thinking, you know, how horrible their last moments were. right. and what that scene looks like. reporter: the trauma unit prepared to receive dozen of uvalde s wounded. the blood has been checked. reporter: the nurse davis recalled the agony wait for patients and overwhelmed