SAN DIEGO (FOX 5/KUSI) — A body believed to be the 50-year-old hiker who went missing on Black Mountain was found Monday morning following more than a day of search and rescue efforts.

Diem “Dina” Le Nguyen began the hike at Nighthawk Trail with a large group of people around 8 a.m. on Sunday, San Diego Police Department Lt. Dan Meyer said.

The hike was part of an annual 5k fundraiser for the nonprofit, Build a School Foundation. According to organizer Jimmy Thai Dtm, part of the group turned around midway to the top, while Le Nguyen continued up to the summit with those that stayed on the hike. The family members she was with were among those who opted to head back down early.

She can be seen in a livestream by Thai Dtm of the group at the mountain’s summit taking the picture that was later distributed when she went missing. At another point in the video, she can be seen headed east, apparently beginning the trek back to the bottom of the mountain.

Le Nguyen was last seen by the group at about 9:30 a.m. Around 10:08 a.m., she made a distress call to her sister, saying she was “extremely hot and needed water,” according to Meyer. That was the last anyone heard from her.

Authorities said Le Nguyen was considered “missing at risk” due to the difficulty of the trail and the extreme heat in the hours after she went missing. An excessive heat advisory was in place at the time she went missing.

Search and rescue efforts began, led by San Diego police, San Diego County Sheriff’s Department and park rangers. The search for Le Nguyen continued overnight, as a ground crew and three helicopters searched the area until 1 a.m.

At 7:30 a.m. Monday, search and rescue efforts resumed. Then around 9:15 a.m., police were notified a body had been found. The body was first spotted by a helicopter, and first responders were sent to the location, where they confirmed it was the body of an Asian female.

The body was found about a quarter-mile from the intersection of Carmel Mountain Road and Via Remeni. According to SDPD, she likely became confused about where she was given the twists and overlaying trails on Black Mountain while enduring heat-related exhaustion.

“She nearly made it out,” Meyer said.

Shortly before finding the body, crews had found a hat, but it was too soon to know whether it belonged to the hiker.

The San Diego County Medical Examiner’s Office will investigate the death and confirm the body’s identity. Authorities have notified Le Nguyen’s family of their discovery.