YARMOUTH, Nova Scotia – Federal labor inspectors wrapped up their on-site investigation into a gangway collapse at the Yarmouth ferry terminal that injured three workers, officials said Friday.

Investigators are trying to determine why the enclosed gangway between the terminal and the Cat ferry crashed 30 feet to the concrete wharf Tuesday after steel cables apparently let go.

Sections of a broken cable along with retaining pins are being analyzed, said Michael Grace, spokesman for the Canadian equivalent of the U.S. Occupational Safety and Health Administration.

The injured men were inside the gangway as it was being positioned to receive passengers from the Cat, which operates between Yarmouth and Bar Harbor, Maine.

The government also will conduct interviews with the three injured men. A preliminary report should be completed in about a month, Grace said.

Shawn Cummings, a Bay Ferries Ltd. employee, and MacKenzie Security staffers Aubrey Williams and David Giles, were listed in fair condition. The trio have multiple fractures and other injuries.

Ferry service wasn’t disrupted by the accident and both the high-speed Cat and the Scotia Prince maintained their schedules to Maine on Wednesday and Thursday.

Foot passengers must use vehicle ramps to board and disembark from the ferries until the gangway is cleared for use.