News bites: Tesla pays off DOE loan, Shell on oil price probe and more

Tesla CEO Elon Musk says the electric car firm will likely pay off its Energy Department (DOE) loan Wednesday, Bloomberg reports.

Royal Dutch Shell CEO Peter Voser says it's too early to speculate about a recent European Union probe into potential oil price manipulation by Shell, Statoil and BP, Bloomberg notes.

The Daily Beast discusses whether climate change contributed to the tornado that struck Oklahoma on Monday.

USA Today takes a look at the progress of President Obama's "Better Buildings Challenge," a program that encourages energy efficiency.

Scientists urged federal officials to maintain Endangered Species Act protections for the gray wolf, The Associated Press reports.