It took the lives of 24 people, including seven children sheltering in a hallway at school.
The Moore tornado that hit May 20, 2013, changed the landscape in central Oklahoma, and changed the way people around the world respond to disasters.
The EF-5 tornado killed two-dozen people, wrecked hundreds of homes and businesses and destroyed two elementary schools.
But one year later, Moore is doing better than expected, and that's in part because of all the help they received. More than $70 million dollars came in through the American Red Cross and United Way donations. But those organizations are used to dealing with disasters.
Jim Corbett, Moore financial director, said the community received much more financial support this storm compared to previous disasters. It was the third time in 15 years a powerful tornado struck the community.
"We had people from probably all the states and even foreign countries sending us money," he said. "Some of it was foreign currency."
Corbett said he believes the difference in 2013 was that children died in the storms.
"Plaza Towers elementary, there were seven children that were killed there, and I think that touched people across the world."
Many who couldn't donate financially, volunteered their time, said Chris Fox, a local pastor.
"We had people who wanted to give help, we had people who needed help, and our job was to connect them," Fox said. "You suddenly feel like you really are a part of humanity as a whole."
Fox's crew used the power of social media to help clear debris from the town's cemetery.
"In solidarity, our churches said let's keep going," he said. "Let's help people. Let's rebuild houses. Let's build sheds and fences and really help people get from A all the way to Z."
Volunteers continue #servemoore's mission today. The organization pays it forward when disaster strikes in another part of the country.
"It would be great to know that a wheel barrel with a serve Moore sticker on the side of it ends up serving a wildfire, after a flood, after a tornado," Fox said.
Some residents in Moore are moving into their new homes as the first anniversary approaches. But many still have a long way to go.
"While certainly our prayers are that we don't ever experience something like this again, the reality that we know we need to prepare for is that we will," Fox said.
The best way to help victims of tornadoes is to donate cash or gift cards. Moore officials said many of the items sent to the city stacked up in a warehouse, and most of it was eventually given to the Salvation Army.
Back to Moore continues Monday night, where we revisit a neighborhood still working to rebuild.