Here we go, yet again.  Have nooses made a comeback?

I ask because police are investigating a hangman’s noose that was discovered Tuesday morning on the office door of Madonna Constantine, a professor of psychology and education at Columbia University’s Teachers College and author of a book entitled "Addressing Racism: Facilitating Cultural Competence in Mental Health and Educational Settings."  Constantine, who is Black, teaches a class on racial justice.

Teachers College, founded in 1887, describes itself as the nation’s oldest and largest graduate school of education.

According to its Web page, the college brought Black teachers from the South to New York for training in the early part of the 20th century, when schools in the South were segregated.

The college has a diverse student body, including students from nearly 80 countries. The racial breakdown is 12 percent Black, 11 percent Asian American and 7 percent Hispanic.

A student walkout has been planned for 2 p.m. this afternoon, according to ABC News’ New York affiliate WABC.