Short answers, pulled from the story.
The CN Tower officially opened on the 26th of June 1976. Three public observation points were immediately available including the Space Deck at 447 meters and the Indoor Observation Level at 342 meters.
NCK Engineering served as the structural engineer for the CN Tower alongside John Andrews Architects and Webb, Zerafa, Menkes, Housden Architects. Foundation Building Construction handled groundwork while Canron managed steel fabrication during construction.
The CN Tower stands as the tallest free-standing structure on land in the Western Hemisphere within North America. It remains the third-tallest tower worldwide behind Tokyo Skytree and Canton Tower with a height exceeding 553 meters.
Freezing rain created ice layers several centimeters thick that formed sides of the tower plus surrounding downtown buildings before winds blew chunks away. Police closed streets surrounding the tower on March 5 after falling pieces smashed windows and caused damage up to 2 kilometers away.
The CN Tower held the record for 32 years until the 12th of September 2007 when Burj Khalifa surpassed it during Dubai development phase. The tower remained the world's tallest tower until 2009 when Canton Tower in Guangzhou exceeded its height.