LOS ANGELES (AP) — A 13-year-old boy was miraculously rescued Monday after falling into a river of sewage in Los Angeles, getting swept away and spending more than 12 hours in the city’s toxic and mazelike underground sewer system.

Jesse Hernandez had been playing with other children on wooden planks over an access portal to the sewer system during a family outing Sunday at a Los Angeles park. When a plank broke, Jesse fell about 25 feet and landed in fast-moving sewage, said Brian Humphrey, a spokesman for the Los Angeles Fire Department.

The other children immediately notified adults, who called 911, initiating a frantic and exhaustive 12-hour search of labyrinthine underground pipes using cameras propped on flotation devices.

Rescuers finally found Jesse after seeing images of handprints on a sewage pipe. A sanitation crew rushed to the area and opened a manhole.

“The first thing they heard was ‘Help!’” said Adel Hagekhalil, assistant general manager of the sanitation department.

The crew lowered down a hose to Jesse, who was about 11 feet deep in the pipe.

“He caught onto the hose and was reeled back up,” Hagekhalil said.

Rescuers gave him immediate medical attention, including hosing him down to get rid of the sewage and cleaning out his eyes and nose with sterile saline, Humphrey said.

Jesse immediately asked for a cellphone to call his family. A worker handed him a phone, and he called his mom.

The boy later told KNBC-TV that he was tired and a bit scraped up, but otherwise OK.

“I was praying to God to help me and to not die,” Jesse said. “It was all quiet. You could just hear the water running through and you couldn’t see anything. It was dark.”

After an accident like Jesse’s, rescuers say the likelihood of someone being found safe diminishes by the hour.

Hagekhalil said rescuers were thrilled at the outcome.

About 2,400 feet of pipe had been inspected when rescuers found Jesse less than a mile from where he disappeared. He was taken to a hospital for a full evaluation and to be reunited with his family.

In addition to the massive rescue effort involving more than 100 people, Humphrey credited Jesse for his survival. Not only did he survive getting swept through sewage moving at 15 mph, he managed to find a pocket of breathable air and hang on until he was found.

“Any subterranean location, particularly one that involves waste, can produce toxic gases — methane, hydrogen sulfide — so breathable air is a key element,” Humphrey said. “The odds of someone falling into such a pipe and surviving are slim. The odds were not in his favor, and many would call it miraculous.”

He called Jesse “a resolute young man.”

“He has tremendous inner strength,” Humphrey said. “It’s obvious he’s not a quitter.”

Los Angeles Mayor Eric Garcetti was among the many Angelenos closely watching the rescue efforts for Jesse. In a string of tweets, Garcetti praised rescuers and thanked the teen’s family for their “patience and optimism during this harrowing experience.”

“We’re keeping Jesse’s health and recovery in our thoughts today,” he said.

Also Sunday, an 11-year-old boy fell into a canal in Meadow Vista, about 40 miles northwest of Sacramento. He was found dead a couple hours later.

Famously in October 1987, rescuers freed an 18-month-old girl who had been trapped in a narrow, abandoned well in Midland, Texas, for more than 58 hours.

Jessica McClure’s rescue captured the nation’s attention in some of the first round-the-clock television coverage in the U.S.