DETROIT (AP) _ Fire broke out early Thursday outside Cobo Hall, damaging the outside of the convention center where a group of engineers is holding a major exhibition this week. Several firefighters had minor injuries.

Authorities said construction material on a loading dock caught fire around midnight, and the flames spread to the walls of Cobo Hall and adjacent Joe Louis Arena. The fire was under control within an hour.

Damage to the hall and the arena, home of pro hockey's Detroit Red Wings, was being assessed, Fire Battalion Chief Tim McConnell said.

The Society of Automotive Engineers is holding its annual International Congress & Exhibition at Cobo Hall. Thursday is the final day, and it was unknown whether the damage would affect the event.