OKLAHOMA CITY - When severe weather strikes, our storm chasers are usually first on the scene. They show us the storm and who needs to seek shelter. Some are taking their role a step further.

When husband and wife team Sean and Trisha Wilson rolled into Joplin, Missouri on May 22, 2011 as the killer tornado hit, they had two goals: find the tornado and find victims to rescue.

They're part of the Rolling Thunder Disaster Response Team. The idea began when Sean arrived immediately after a tornado flattened Greensburg, Kansas in 2007.

"Just sat beside people and tried to comfort them and nothing I could do," Sean remembered. "It was the most helpless feeling I've ever had in my life."

This helplessness convinced Sean and Trisha they had to do more.

"You can't drive by. You can't say, well I'm sorry that happened to them," said Trisha. "You have to stop and do something."

Trained in advanced first aid and search and rescue, the team's mission is to fill the gap between when a tornado hits and when first responders arrive.

"Those first few minutes. Those golden moments that you know when a person's hurt and needs help," said Sean. "If we can located them quick and get them help, then I think we're going to save a lot of lives."

The team tracked the EF-5 tornado that destroyed part of Joplin, and in the moments thereafter, transported nearly 30 victims to the hospital.

"That's the most difficult part," said Sean. "When you see a human body that is damaged and hurt. That's the worst part of what we do and that can affect a person deeply."

The experience inspired them to not only continue their medical relief efforts following a tornado, but to expand the team and its resources across Oklahoma.

"We can't be everywhere at one time, but if we have teams all around the state, we can get to those areas quicker and be more effective in what we're doing," Sean said.

Through grants and sponsors, this non-profit group plans to have an Emergency Response Vehicle to tow behind their chase truck.

"It's capable of driving through water. It can drive through a lake. It can go over debris," said Sean. "Really, there's nothing that's going to stop this vehicle."

The Rolling Thunder Disaster Response Team does not take the place of first responders. In fact, they're working closely with many local first responders, medical personnel and fire departments to initiate the rescue efforts.