Volunteers trudged through vacant lots, thick with weeds, burrs and trash, and used walking sticks to poke into piles of debris.
Volunteer Gordon Jones, 45, of Detroit hoped for the best but braced for the worst.
"If it were my daughter, I would be looking anywhere and everywhere," he said, as he looked toward a swathe of abandoned buildings.
Jones, a contractor by trade, put his skills to work this morning, entering whatever abandoned home he could access. His flannel shirt covered in burrs and hands protected by workers gloves, he used a flashlight to peer under the porch of a two-story, boarded-up white house whose exterior was riddled with discarded couch cushions and rotting furniture.
"My heart told me to go where other people don't want to go," he said.
Accompanying the searchers were law enforcement officials from Detroit and the FBI. Some walked with the volunteers wearing yellow ponchos.
Others drove slowly down Philadelphia in a marked police van, lights flashing, to keep an eye on any progress. One officer ran toward I-75 on Philadelphia with a burly bloodhound by his side.
Several of the volunteers, including Jones, said it was a call to action by community organizer Tasha Harris that prompted them to brave the weather today to help in the search for Bianca.
Harris, 29, blogged through the night on her site, www.detroithousewives.net, asking that people get involved with the canvassing efforts. Her site and organization of the same name helps at-risk youth stay focused, she said.
Walking with a cane and wearing a black fur coat, Harris said she might not get to physically aid as much as others but was pleased with the response to her blog posts.
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It could have been any one of our children. I instantly felt a connection with the mother," said Jones, herself a mother of two daughters, 10 and 11. "A mother's love goes so far and so deep."