A couple of hikers got lost in the woods and found their flashlight was dying. They successfully used a cellphone flash to signal rescuers.

A man and a woman, who authorities did not identify, alerted emergency workers around 8:30 p.m. Sunday that they had lost their way on a hiking trail in the House Mountain State Natural Area in east Knox County.

Knox County Sheriff's Office used a helicopter to search for the pair, but pilot Tony Chamberlain was unable to locate them with an infrared device that detects body heat because of the heavy foliage.

The hikers' flashlight batteries were losing power, so the woman told authorities by cell phone that she would use the camera flash on the phone to alert the helicopter pilot, who saw the flash using night-vision goggles.

"It was great the way everything came together," said Leigh Ann Cate, executive director of the Knoxville Volunteer Emergency Rescue Squad. "It had a really good ending." The helicopter hovered over the hikers' location until Tennessee Wildlife Resources Agency workers reached them around 9:20 p.m. Neither hiker required medical attention.