(Avondale) -- Beth Dulle is at a loss to explain the disappearance of her son, Brogan.  He spent much of last Saturday with his family, in Anderson Township, before returning to Clifton to go out with friends.  Brogan texted his mother that night, before he disappeared, and made plans for Sunday.  But he never showed up.

Dulle says the first indication they had that something was wrong was when Brogan failed to show up for work.

His parents know of no reason for him to walk away from his life.  They say if there was a problem, they'll deal with it when he gets back.  Beth Dulle says her son is responsible, and this disappearance is out of character for him.

One of Brogan's cousins is helping coordinate the search from Clifton.  Libby MacVeigh says it's keeping her busy, and keeping her from thinking too much about his disappearance.

More than a thousand people volunteered with the search effort this week.  On Thursday, volunteers concentrated their efforts in a five-mile radius from where Brogan was last seen.  Friday, they expanded that to ten miles.

MacVeigh says every team has to check back in when they're done, because they don't want another missing person.  She says they're hoping they don't have to continue the search into the weekend.

Meanwhile, Cincinnati Police say they have no new credible leads in the disappearance.  Captain Elliot Isaac says they still haven't found Brogan's cellphone.  It's what he left his apartment to find, early Sunday morning. 

Police technicians are still trying to get into Brogan's computer and tablet, to see if there's a clue.  And a search of Metro bus video has turned up nothing.  Brogan did not have a car, and primarily traveled by bus.

Captain Isaac says they don't know why the 21-year-old vanished, and they're not ruling anything, include foul play, out.

Anyone with any information that might help the search is asked to contact Crimestoppers at 352-3040.