From VOA Learning English, this is the Technology Report.

The deadly tornado in Moore, Oklahoma has wind speeds of 400 kilometres an hour. 24 people were killed when the storm cut a path of destruction through the city.

With only a 15 minutes' warning, people fled Moore, or took refuge in the most secure area of their homes or other buildings. The lucky ones took cover in underground shelters, or steel-and-concrete structures called safe rooms.

Leslie Chapman Henderson is head of a non-profit group called the Federal Alliance for Safe Homes. The home safety activists is a big supporter of tornado safe rooms. She says they can help reduce the number of tornado deaths.

"The safe room is an interior room of the home that has been reinforced and tested and certified to withstand high wind and debris impact of the type that we've just seen happening in Moore, Oklahoma. In fact, we've already heard of families and stories of survival of people who were in safe rooms, either above ground, or below ground."

Skye Strouhal of Moore was one of those people, he watched as the tornado moved in his direction, he and a friend run to a neighbor's underground shelter only minutes before the storm struck.

"It was getting a little too scary for me and I followed him back there into that backyard and we tried to open that cellar and it was locked by a chain, and then they let us in and shortly after that (the storm) was on top of us."

Better methods for predicting storms give people like Skye Strouhal and his friend more time to react, but they need someplace safe to go. Buildings can be built to resist strong winds, but not like those in the tornado that struck Moore. It was rated an F-5, a tornado with the fastest wind speeds.

Leslie Chapman Henderson says even the building codes or laws that do exist, are not widely used or enforced.

"There are places at the EF-0, 1 and 2 level where a building code can make a difference. But what we really need here is a combination of both the code and the safe room."

Most of the ruined structures in Moore had neither. Only one in ten homes there have tornado safe rooms.

Moore sits in a central area of the United States called tornado alley where such storms are common. This is the fourth severe tornado in the city in fourteen years.

But Leslie Chapman Henderson says memories do not alway last. Neither of the two elementary schools destroyed in Moore had safe rooms. Those rooms, she says could have saved the seven children who died.

"I think we need to focus on our schools, and we need to set a minimum standard of always having a safe room option for students. What we've learned here tragically is that is the most important investment that we can make."

As the people of Moore start to rebuild, its mayor is pushing for new laws requiring safe rooms in all new buildings. Similar proposals were made following each recent tornado strikes, but none such laws have been passed.

And that's the Technology Report.