DETROIT (AP) — U.S. safety investigators say electric vehicle fires pose risks to first responders, and manufacturers have inadequate guidelines to keep them safe. The National Transportation Safety Board also said in an 80-page report Wednesday there are gaps in industry safety standards and research on high-voltage lithium-ion battery fires, especially in high-speed, severe crashes. The agency has no enforcement powers and can only make recommendations. It called for manufacturers to write up vehicle-specific response guides for fighting battery fires and limiting chemical thermal runaway and reignition.