The heartbreaking mystery surrounding the disappearance of 7-year-old Kyron Horman in Oregon drew hundreds together for a prayer vigil.

About 400 friends, neighbors and total strangers gathered Tuesday evening at Sunset Presbyterian Church, hoping for the boy's safe return.

Kyron disappeared from his Portland-area school June 4. After search teams combed the area for days, authorities announced they would now follow his case as a criminal investigation.

"We're all incredibly heartbroken, yet have hope at the same time Kyron will be returned to [his] family safe and sound. That's what's helping us through," Skyline Elementary School principal Benjamin Keefer said.

Those who gathered at the vigil also prayed for Kyron's classmates. Many are shaken by the fact that Kyron's stepmother last saw him walking down a school hallway, only feet away from his classroom.

"[A] crisis like [this] pushes us to pray and to turn to God," Pastor Ron Kincaid said during the service. "So that's what we're doing tonight."

For many in the neighborhood, prayer is the only comfort.

"A lot of times vigils have a negative connotation -- mourning and loss," one attendee said. "That is not what this event is about at all. This is, we are hopeful. We support the family. We are praying for Kyron's safe return."

Vigil organizers passed out missing child fliers with Kyron's picture. Attendees also submitted "encouragement cards" for the family, giving them kind words and support.