When Decker, 17, took some bread out to the mallard mom and found her standing over a metal storm drain grate, he knew something was wrong.
The duck wasn't interested in the bread and appeared to be looking into the grate.
"She was quacking away," he said.
As Decker, a senior at Smithsburg High School, approached, he heard the cries of duckling coming from beneath the grate. He realized the ducklings had fallen through and were trapped in the drain.
Knowing he couldn't lift the two-inch thick steel grate, Decker tied his Ford F-250 full-size pickup truck to the grate, stepped on the gas, and pulled off the grate.
The mama duck kept tabs on what Decker was doing, quacking at him the whole time.
"She didn't get more than 30 feet away," he said.
Decker got a bucket and reached into the storm drain. He scooped up two of the ducklings, which he estimated were a couple of weeks old.
"As soon as I got the second one up she took off with them," he said.
A third duckling wasn't so lucky. "It must have broken its neck in the fall," Decker said.
He buried the duckling in his back yard, the burial ground for deceased family pets.
These days, the family has a dog, three cats, a guinea pig and some fish, he said.
"I was thinking about getting a hedgehog but I don't have anywhere to keep it right now," he said.
Two of the cats were strays and the dog came from the Humane Society. Decker chose the dog because it looked like it was getting picked on by the other dogs, he said.
Decker said he might like to become a veterinarian or work for the SPCA.