The Notre Dame cathedral in Paris was closed Tuesday after a French historian shot and killed himself at the landmark’s altar. Dominique Venner, 78, was a far-right-leaning French historian and had written a blog post expressing his anger over the country’s recent legalization of same-sex marriage. Before shooting himself, Venner put a letter on the Notre Dame altar—it’s not clear what the letter said or whether it indicated a motive. Marine Le Pen, head of the far-right Front National, tweeted that she had “respect” for Venner and found his death to be an “eminently political” gesture.