Why did a Dallas apartment complex explode??

Recovery efforts continue after a massive explosion and apartment fire in Dallas. It was caused by a gas leak, but who caused the leak? The NBA thinks it may have come up with a solution to its "tanking" problem. What happens when there's a tie in the National Spelling Bee? They move on to a "lightning round," of course. Texas Senator Ted Cruz is working on a way to protect college football from itself. How serious does he feel this problem is? He's teaming up with a Democrat to come up with a solution.