LOS ANGELES >> A 13-year-old boy was miraculously rescued today after falling into a river of sewage in Los Angeles, getting swept away and spending more than 12 hours in the toxic environment of the city’s mazelike underground pipeline 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.

“He was happy, the family was happy,” said Hagekhalil, adding that rescuers were thrilled at the outcome.

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

“They never gave up hope,” he said. “They wanted to bring Jesse back to his family.”

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, authorities said.

“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.”

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.