The lingering grief caused by 9/11 terror attacks is a reminder of strong ties between Canadian and American people despite the current political climate and trade tensions, said the mayor of St. Catharines, Ont., as the city expands its memorial for victims.

This Friday marks 25 years since nearly 3,000 people in the U.S. were killed when al-Qaida hijackers slammed planes into the World Trade Center twin towers in New York and crashed into the Pentagon and a Pennsylvania field.