'All we can do is wait and hope' - aerial footage shows extensive search for Irish man missing in California
The brother of an Irish man who has been missing in America since last year has said his family are still hopeful that the "unbelievable" search effort will provide answers.
David O'Sullivan (26) from Midleton, Co Cork, has not been seen - or heard from - since April 2017.
He left Ireland on March 20 for a five-month hiking trip from California to the Canadian border.
David last made contact with his family on April 7, when he sent them an email from the mountain town of Idyllwild.
The aerial footage below shows the extensive searches being undertaken by volunteers in the US.
Commercial pilots and aerial surveyors teamed up to conduct an aerial survey mission over Idyllwild this week.
David's older brother, Niall O'Sullivan, told Independent.ie that his family are overwhelmed by the response from "complete strangers".
"We're delighted with the search efforts so far and with absolutely everyone who has volunteered. The response has been unbelievable. And all we can do at the moment is wait and hope that the photographs can point us in the right direction."
Niall described David as a novice hiker who was inspired to hike the Pacific Crest Trial last year.
There has been no activity on his brother's bank account in the past eight months, except for a number of direct debits.
His parents travelled to California in December to participate in what was described as the "biggest search party yet".
Any financial donations to future searches can be made here .