The similarities to the Sandy Hook school shooting in 2012 and Tuesday's Texas school shooting are glaring and painful.

That heartache and helplessness was felt from Newtown to our nation's capital, and it leads many to ask one question - how is it possible that this is still happening?

"What are we doing? Days after a shooter walked into a grocery store to gun down African American customers, we have another Sandy Hook. What are we doing? Our kids are living in fear every single time they step into a classroom because they think they're going to be next," said Sen. Chris Murphy hours after the shooting in Uvalde, Texas.

This is the second deadliest elementary school shooting since Sandy Hook in 2012.

The parallels to Sandy Hook are chilling and unavoidable.

In 2012, Adam Lanza killed his mother, then drove to Sandy Hook Elementary and opened fire. The Uvalde suspect, 18-year-old Salvador Ramos, killed his grandmother, then drove to Robb Elementary to carry out his acts of violence - shooting indiscriminately at 7, 8 and 9 year olds.

MORE: Biden says 'we have to act' after Texas school shooting
MORE: 'What are we doing?' Sen. Chris Murphy challenges Republicans after Texas school shooting

The families in Uvalde, just as in Newtown nearly a decade ago, are now seeing their worlds shattered.

"I think all you need to do is look at today's event and the similarity to Sandy Hook to know that it keeps on happening and we haven't found a fix for it yet," said Kenneth Gray, retired special agent with the FBI. "This is a tragedy that no parent should have to go through."

Gray is also a senior lecturer at the University of New Haven. He says there is not one cause for events like these or one single solution, but Murphy says the time to do something is now.

"Why are we here if not to solve a problem as existential as this? This wasn't inevitable. These kids weren't unlucky. This only happens in this country, and nowhere else," Murphy said.