New technologies have made vehicles safer than ever for motorists. Not so much for rescuers responding to car accidents.

USA Today has a fascinating look at how cars have changed in ways that make rescues both more complicated and more dangerous for first responders.

Chris Woodyard writes that "firefighters and other first responders now face a host of unknowns at the scene of any serious auto accident."

Among them: New types of steel that are more difficult to cut, high-voltage cables in hybrid or electric cars and keyless ignitions which make it harder to discern whether the engine is running.

USA Today looks at the problems – and at some of the proposed solutions.