It was an ordinary summer day for Marcia Hess, her 12-year-old daughter Madi Hess, and 2-year-old son Thorin on Tuesday, with the kids spending time under the sun in their grandparents’ Edgewood backyard.

But idyllic turned to tragic when Thorin slipped and fell through a hole in the yard, straight into his grandparents’ septic tank.

Madi, who witnessed her baby brother’s fall, felt paralyzed with terror in the moments immediately following.

“All I felt was just terrified — I didn’t know what to do,” Madi told KIRO Radio’s Dori Monson. “If I could, I would’ve just laid down and started crying on the grass … It was so scary.”

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Instead of giving in to fear, however, the proactive girl ran into the house to alert her mother, and then called 911 while her mom ran to where Thorin was trapped.

“When I got to the hole, I could see him — he was face-up, and I could see him,” Marcia said.

She ran to get a shovel for Thorin to hold onto until paramedics could be at the scene.

What followed was an agonizing series of near-saves and misses. Thorin grabbed the shovel, but let go and fell back into the water.

“I tried to use the shovel to try to find his head and prop his head up until the paramedics got there, but I couldn’t find him,” she said.

When Thorin’s shoe got caught on top of the shovel, Marcia was able to get Thorin to the top of the hole. Madi got ready to grab her brother, but at the last moment, “his shoe came off in the process and he felt back in,” Marcia said.

Having exhausted all other options and with time running out, Marcia knew she would have to go in.

“At that point, I knew that the shovel was not going to work — there was no other option,” Marcia recalled through tears.

Marcia worried that she would not fit into the hole, which she described as “a shoebox size,” with an opening that was barely wider than a basketball hoop.

“I just got down there and shoved my feet in … and I just prayed out, ‘God, get me down there,'” Marcia said.

She was unable to see while inside the septic tank hole, but she managed to locate and pick up her son, then hand him up to his sister.

The ordeal was not over, however — upon grabbing Thorin, Madi was horrified to see that her brother was not breathing.

“When my mom had brought him up, his face was blue and purple, and he was completely limp, his eyes were wide open, and I thought he was actually dead,” she said. “But then something in me told me that he was still holding on … I knew that he was still there.”

Madi hadn’t had any formal CPR training, but she had seen it administered on TV shows. Although she could no longer hear the 911 dispatcher’s advice due to the chaos, she began giving her brother the live-saving procedure.

“At that point, I just kind of gave up and I just went on my own with it, because I couldn’t hear the dispatcher … there was a lot of yelling going on around me,” she said.

After a series of harrowing moments, Thorin rolled his head to the side and made a noise.

“I kept on going, but just a little bit harder with my palm, and he started gurgling,” Madi said. “And then he coughed up a bunch of water, then he started crying.”

Thorin was rushed to the hospital, where he was treated with antibiotics. Luckily, there doesn’t seem to have been any permanent harm done.

“He’s back to his old self,” Marcia said.

As for big sis Madi, Dori asked if she will ever use the “You’d better be nice to me, I saved your life” card with her brother in the future.

“Definitely,” Madi laughed.

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