Students, parents and teachers shared their fears and tears at the White House Wednesday. And one grieving father captured the nation's attention as he expressed the pain he's feeling after losing his daughter in Florida.

President Trump held a "listening session" where he heard from student survivors and parents personally affected by mass schools shootings.

"We're here because my daughter has no voice. She was murdered last week and she was taken from us," Andrew Pollack said. "We as a country failed our children."

Pollack's 18-year-old daughter Meadow was one of the 17 killed at Stoneman Douglas High School in Parkland, FL last week.

"How many schools, how many children have to get shot? It stops here with this administration and me. I'm not going to sleep until it is fixed. And Mr. President, we'll fix it. Because I'm going to fix it. I'm not going to rest. And my boys need to live with this," he said.

"This shouldn't happen. We go to the airport, I can't get on a plane with a bottle of water, but we leave some animal to walk into a school and shoot our children. Fix it," Pollack pleaded.

"It should have been one school shooting and we should have fixed it and I'm p***ed. Because my daughter, I'm not going to see again," he said. "King David Cemetery, that is where I go to see my kid now."

President Trump offered some ideas on how to prevent more attacks, including arming some teachers and giving them special training.

"An attack has lasted, on average, about three minutes. It takes five to eight minutes for responders, for the police to come in. So the attack is over. If you had a teacher who was adept at firearms, they could very well end the attack very quickly," Trump said.

But Mark Barden, whose son was killed in the Sandy Hook school shooting in Connecticut, disagreed. "Schoolteachers have more than enough responsibilities right now than to have to have the awesome responsibility of lethal force to take a life."

On Twitter Thursday, Trump tried to explain more clearly what he meant, that he didn't think all teachers should be given guns.

"I never said 'give teachers guns' like was stated on Fake News CNN & NBC. What I said was to look at the possibility of giving 'concealed guns to gun adept teachers with military or special training experience - only the best,'" he said.

Several parents from the Sandy Hook elementary school massacre were also part of the session.

"No parent should go through this," said Nicole Hockley whose son was killed in Sandy Hook.

"And after Sandy Hook, they said we wouldn't let this happen again and yet it has continued to happen for five years. How many more deaths can we take as a country? How many more teenagers and 6 and 7 year olds can be allowed to die? Don't let that happen anymore on your watch."

The president meets with state and local officials Thursday to talk about school safety.