Yesterday’s events were a devastating human tragedy. Two hijacked planes, together carrying more than 100 passengers, were crashed intentionally into each of the twin towers of the World Trade Center. Another crashed into the face of the Pentagon building in Washington, and a fourth went down 80 miles outside of Pittsburgh. Authorities have resisted reporting the number of possible victims, but it is likely to be in the tens of thousands—each a father or a mother, a friend or child.

The Crimson grieves and feels deep sympathy for the families and friends of those who suffered in the deadliest recorded assault on American soil. But the victims of this tragedy are found not only in New York, Washington or Pennsylvania, but across America and throughout the world—those who have friends and family in the cities targeted, and those who have been emotionally and physically shaken by this brutal and unexplained violence. Yesterday’s events were an attack on the security of all Americans, and all Americans share the weight of mourning and the responsibility of assisting those most in need.

The attacks took place at the beginning of the workday, timed to hurt as many innocents as possible. More than 50,000 people worked in each tower of the World Trade Center in an average day, and although many were fortunately able to escape, thousands are still feared dead. Much of Manhattan was covered by the rubble and dust of the collapse; residents were evacuated from parts of the island as bridges and tunnels were closed. The city itself was disfigured by the blasts, the most prominent features of its skyline now twisted piles of concrete and steel. Despite the long work of rebuilding that lies ahead, many of the deepest scars will never disappear.

Never in recent memory, not even in wartime, have the president and Cabinet, as well as both houses of Congress been evacuated to “undisclosed locations.” The attack on the Pentagon struck the heart of defenses that for so long had appeared impenetrable.

We grieve also for those on board the hijacked planes, both passengers and crew, many of whom lived in Boston. The stories are slowly filtering out about passengers’ frightened calls over cellular phones, attempts to contact loved ones in the midst of crisis. The sense of safety in our city was quickly dispelled by the realization that terrorists had boarded planes at Logan Airport just yesterday morning; government buildings and landmarks such as the Prudential Center and John Hancock towers were closed, and the MBTA public transportation system generously waived all fares in an attempt to help workers reach their homes.

In Cambridge and on our campus, the morning hours were particularly frightening, when news was scarce and phone systems were overloaded by frantic calls home. Students registering for the semester tried to spend as little time as possible in the Yard, fearing that it, too, might come under attack. Suddenly every parked truck became a car bomb, every University building a potential target; a number of buildings, including William James Hall, were closed for fear of renewed violence. House common rooms filled with students who watched the coverage together; grief and shock were apparent on the eyes of many who were directly affected by the blast or who are now counseling friends and loved ones.

Yet amid the mourning, we are comforted by examples of the highest form of human spirit. The Boston-area Red Cross was overloaded with offers to donate blood to help the wounded, and a University-organized blood drive will begin soon. Although commercial air traffic has been shut down, Harvard Medical School-affiliated hospitals will be participating in the effort to save lives as the Air Force shuttles wounded individuals to Boston. We thank the University and President Lawrence H. Summers for their efforts to make additional counseling resources available and to provide news of Harvard’s family, and we are grateful to the tutors and House Masters who contacted their students and offered their support.

The vigil held in Tercentenary Theatre yesterday afternoon was striking for the thousands who convened in the Yard and sat in respectful silence for over half an hour during the moving ceremony. This vigil was a testimony to the unity that the Harvard community can develop—and that we have the responsibility to sustain—in the face of tragedy.

Yesterday’s attacks were all the more frightening because they did not require sophisticated technology, only knives and organization. They are frightening because of the inhumanity of those who made airplanes bearing scores of passengers into weapons and because of the attacks’ seemingly random and inexplicable nature. These actions of unnamed terrorists—for as of yet no known political cause, for no end but violence—were intended to inspire fear in all human beings who only wish to live their lives in peace.

We hope that those who chose to take so many lives will be brought to swift justice, and that our government takes effective measures to restore Americans’ sense of safety.

But there will be time enough for such efforts in the coming days. For now, the most important work must be done by individual Americans. Emergency crews, the National Guard, medical professionals and selfless volunteers are already donating their services and risking their lives to save as many Americans as they can.

In return, we must pledge our support and show our solidarity with these brave men and women. The demand for emergency rescue and relief is certain to continue for weeks, if not months. When the president addressed the nation last night, he said that this attack is a test, and it is a test that we all must resolve to pass, together.

In the face of this tragedy, we must devote ourselves to mourning the dead, treating the wounded and comforting the bereaved—secure in the knowledge that we as a peaceful society are stronger than those who would threaten our freedom.