HOUSTON -

They're popular at birthday parties and festivals; but there are new concerns today about inflatable bounce houses after another one went flying through the air over the weekend, injuring two children.

This is the second time in less than a month that an inflatable bounce house went airborne with children inside. There are some simple but important steps you can take to secure inflatables if you're renting one for a party.

Panic and fear in Colorado when a bounce house takes off into the air with two young children inside. Parents and players watched helplessly as a gust of wind blew the inflatable slide across a field.

"We thought the girls were going to get taken out cause this thing's massive," said one parent.

A 10-year-old girl was thrown from the bounce house; but an 11-year-old boy continued to tumble another 200 to 300 feet. Both are recovering from minor injuries. The Colorado company operating the inflatable says it maintained all safety precautions including having staff onsite.

A spokesman added "We did have the inflatable properly staked to the ground. We do wish that we had been able to foresee the microburst wind and shut the ride down prior to this incident occurring. And that in no way, shape or form were we trying to operate that ride in those winds."

Just last month, three children playing inside a bounce house in New York were sent flying. And in 2011, 13 people were injured when another bounce house was swept into a crowd in Long Island. That same year an accident was caught on camera at a graduation party in Arizona.

Experts say bounce houses are safe if they're operated correctly. They should be secured with an 18 inch stake at a 45-degree angle, pushing as far into the ground as possible.

You need to be aware of the weather as well. Most bounce houses shouldn't be used if the wind exceeds 20 miles per hour. Every inflatable has a warning label on it about how to use it safely.

The Texas Department of Insurance licenses companies that operate bounce houses. You can search for any company to make certain its licensed before you hire them here.