Pieces of a construction crane that collapsed in the Kingdome last week, killing two workers, were lowered and laid out on the stadium floor Sunday by investigators searching for the cause of the accident.

King County officials said they hoped to know by the end of the week when work to refurbish the dome's ceiling could resume. But state officials refused to speculate on when the investigation would be completed."Investigators worked through the weekend, but there is no time line at this point on when they will complete their investigation," state Department of Labor and Industries spokeswoman Suzanne Taylor said Sunday.

"We can't commit to a date. Investigators are working as hard has they can, hoping to get people back to work as soon as possible."

After the on-site, physical investigation is completed, a "wall-to-wall" investigation will be conducted, Taylor said.