WATERVILLE — A section of Messalonskee Stream was drained overnight as investigators today continued to look for clues in the disappearance of toddler Ayla Reynolds.

Investigators examined Dumpsters, garages, backyards, ball fields and small wooded areas near the Violette Avenue home where the 20-month-old girl was last seen sleeping in her bed.

“In a quick briefing, the warden service said it had been drained down because they were going to walk the banks and there would be a flyover,” Waterville Police Chief Joseph Massey told reporters this afternoon. “And because of the low water, as you might expect, visibility would be a lot better.”

As the search entered its fourth day today, investigators have come up empty. Overnight temperatures have dipped into the low teens and single digits the last few nights.

Massey said his department, the Maine Warden Service and the FBI are intensifying their efforts to find the little girl. The FBI is conducting a “knock and talk” campaign on several nearby streets looking for answers.

“It’s still a missing child case,” Massey said. “I’m not going to speculate on whether she’s alive or when she might come home. We need to follow the logical conclusion of a logical sequence of events. We’ve ruled nothing so I don’t want to stand here and speculate.”

Ayla was reported missing by her father, 24-year-old Justin DiPietro, just before 9 a.m. Saturday, about 10 to 12 hours after he said she was put to bed Friday night.

She was last seen wearing green, one-piece pajamas with polka dots and the words “Daddy’s Princess” on them. She is 2-feet 9-inches tall, and weighs about 30 pounds.

Her left arm is in a sling and soft splint. She has short thin blonde hair.