Academic institutions in New York and Washington, across the Ivy League, and even on the opposite side of the country made changes to routine schedules after Tuesday’s attack. Counselors and support groups on college campuses across the country are now available around the clock for students grieving.

Both Columbia University, in upper Manhattan, and New York University, in lower Manhattan, canceled classes immediately Tuesday.

At NYU, classes are also canceled today, but expected to resume Thursday. Students, faculty, staff and buildings of the university remain safe, according to a statement posted on the NYU Web site. However, five of NYU’s student residences in lower Manhattan were closed since they were in the area evacuated by city authorities.

In the heart of the disaster, NYU opened numerous facilities for student assembly, including the University Health Center.

Columbia administrators said they will re-open classes where possible Wednesday. However, Columbia made many changes to regular schedules, indicating the university will not return to business as usual when classes resume. The university has made sleeping accommodations available for commuting students and staff.

In Washington, only selected college campuses canceled classes. At George Washington University, classes canceled Tuesday are expected to resume Wednesday. At Howard University, classes were held Tuesday.

Besides Columbia, the University of Pennsylvania was the only Ivy League school to cancel classes Tuesday. Ivy League university presidents addressed students several times throughout the day, each time expressing surprise and outrage over Tuesday’s terrorist attacks.

“This has been a day of tragic and horrible loss,” said Princeton President Shirley M. Tilghman in a statement to students. “And as a university community we want to do anything we can to be helpful to those in need.”

In trying to come to terms with this tragedy and to provide necessary services for students, many schools kept classes running but made them optional for students and staff. Many colleges stated that classes should be used for whatever purposes most fit for students and staff.

“All of us are shocked and saddened beyond words by the events of this morning,” said Harvard President Lawrence H. Summers in a written statement to students yesterday. “Harvard has suspended most of its academic activities and faculty and staff have been assured that they may leave as their personal needs require.”

Across the country in California, Stanford University held a vigil at Memorial Church at noon and again Tuesday evening with the Rev. William McLennan Jr., the dean of religious life. A discussion among experts on terrorism took place Tuesday afternoon at Stanford’s Woodrow Wilson School. Classes at Stanford Law School were canceled Tuesday.