Indonesia is battling its worst wildfires in more than a decade, made worse by El Niño. Many were deliberately set to clear land for farming, including palm oil plantations. More than 12,000 schools across Indonesia have closed because of the toxic haze. Natanael Undas, a school principal and photographer, has been documenting the fires on social media.

When actor Christina Applegate revealed that she had been misdiagnosed with multiple sclerosis, it triggered not only an outpouring of empathy for her, but raised important questions about how often people are told they have the condition when they don't. William Brangham discussed why MS can be so difficult to diagnose with Dr. Michael Kornberg of Johns Hopkins University.

Applegate revealed that despite the misdiagnosis, she still has "every symptom of someone with MS," adding, "I still have to use wheelchairs when I go to the doctor's office. I can't walk from the car to the room."

In the years after the 2010 BP oil spill, the number of fish in the deeper parts of the Gulf of Mexico dramatically declined.

Electric aviation is still in the very early stages of its development. But a number of companies are moving forward with more ambitious plans. In contrast to its approach with other forms of electric transportation, the Trump administration seems willing to embrace a bigger rollout. Aviation correspondent Miles O'Brien reports on the promise and the challenges of the budding industry.