PORTLAND, Ore. — The search for 7-year-old Kyron Horman soldiered on today, a week and a half after the boy mysteriously disappeared.

After Kyron didn’t return home on his school bus as scheduled on June 4, his family called the elementary school, which then called police. The official search began at 4:33 p.m.

According to the Multnomah County Sheriff's Office, Kyron's stepmother said that she last saw him about 8:45 that morning, walking down the hallway toward his classroom. She had toured the school science fair with him, where he had shown off his project on tree frogs.

School staff later reported to police that they did not see Kyron after 8:45 a.m. and that he did not make it to his classroom.

An article in The Oregonian said that Kyron's teacher marked him absent at some time during the day, but no call home was made because the school did not have an automatic notification policy — although that has since changed.

“The reported disappearance of a student from one of our schools is unprecedented and deeply troubling,” Portland Public Schools Superintendent Carole Smith said. The district “is doing everything we can to assist the authorities in their effort to find Kyron.”

After Kyron’s disappearance, the district’s crisis responses team was dispatched to the school to offer counseling, and two school resource officers were put in place to provide enhanced security.

Smith said that a number of additional steps were being taken for schools throughout the district, including mandating the use of the district’s automated attendance call system at every K-8 and K-5 school so that families will be notified of any unexcused absence during the day the absence is recorded.

Also, the district is convening a team of leaders “to review arrival and dismissal practices and identify ways we can ensure a smooth, well-coordinated transition of student supervision between families and teachers at the beginning and end of the school day,” Smith said. “As part of this effort, we will review our visitor sign-in practices for school events that invite large numbers of family members and community members into our schools.”

In a press briefing yesterday, Multnomah County Sheriff's Office Capt. Jason Gates said that from June 5 to 12, there was a total of 1,300 searchers in the field — “possibly the largest search operation of its kind in the state of Oregon.”

Gates said that the next phase of the investigation would include a secondary canvassing of the neighborhood and school.

A photo taken of Kyron with his science project on the morning of his disappearance has been circulated in the media, on posters and in missing-person shirts that his family ordered to give out.

The sheriff’s office “is steeled in its resolve to not let this become a cold case,” Gates said. “We are focused on this investigation, and we remind all citizens of the $25,000 reward for information leading us to Kyron.”

Police urged anyone with information on Kyron’s whereabouts to call the Multnomah County Sheriff's Office tip line at (503) 261-2847, or to dial 911 with emergency information.