Investigators combed through debris and pieces of a damaged crane Thursday in Milford, Conn.
They were trying to determine what caused a wall to topple at a power plant construction site, killing two men and injuring two others the day before.
The answers as to what triggered the partial building collapse will be slow coming, officials said in a press conference Thursday morning.
Meanwhile, all work at the site has ceased until further notice.
A portion of the steel-framed boiler building under construction for the plant collapsed Wednesday onto a 20-ton construction crane, pinning its operator inside for eight hours.
"To speculate about anything before the investigation is complete would not be helpful," Brent Freeman, project manager for Black & Veatch Inc., the Kansas company building the plant told the Connecticut Post.
At the press conference at the edge of the accident scene, officials reiterated the only solid conclusion drawn so far about the sequence of events leading up to the accident.
"The position of the debris and the physical evidence indicates that the building fell on the crane; the crane didn't fall on the building," said state Deputy Public Safety Commissioner George Luther.
The boiler building was 80 feet high, about the height of a four-story industrial building, although it was not yet completely enclosed.
The Post reported that Freeman defended the construction company's safety record and said that Black & Veatch was employing a frequently used construction method to erect the building.
The method involved welding or bolting structural steel panels onto a steel frame, the project manager said. The method has been used for some time, including at a power plant the company constructed last year in Massachusetts.
Officials say weather has not been ruled out as a factor in the collapse.
Work at the site will not resume until OSHA officials and state police clear it, Freeman told the Post.