At 3:23 p.m. on Monday afternoon, less than one hour after two devices exploded near the finish line of the Boston marathon, the Red Cross of Eastern Massachusetts announced that no blood donations would be accepted anymore. So much had been given already that stocks were amply replenished. This extraordinary occurrence was to be the mere beginning of a week of altruism, humanity, and kindness in the midst of anguish.

As much as the marathon bombings and Thursday night’s shooting of MIT police officer Sean Collier showed the severity of the pain that we can inflict on each other, the actions of countless community members in greater Boston put on display the best sides of our communities. We congratulate and warmly thank Boston’s law enforcement officers, Harvard staff members, and citizens in the broader community for their unyielding resilience throughout a week of tragedy and fear.

Thousands of police agents swept the streets of Boston on Friday in search of suspect Dzhokhar Tsarnaev, believed at the time to be armed and dangerous, while an entire city contributed to the policing effort with admirable and almost martial unity. The empty streets of Boston testified to the trust that citizens put into Boston’s leaders and law enforcement agents, ceding to no panic or political squabbles.

Workers who were called to their tasks did not hesitate to respond dutifully as the entire city shut down. At the request of the police, select cafes and restaurants remained open throughout the day to provide for officers and emergency workers. Here at Harvard, University Dining Services and Campus Services workers toiled to serve the needs of the student population without wavering for a moment.

The Boston Police Department and Cambridge Police Department published dozens of updates via their Twitter profiles beginning early Thursday night. The police’s use of social media during Friday’s manhunt was crucial not only in keeping people constantly up to date with the events, but also in soothing nerves and fears.

At a time when the shock and horror at the happenings of Monday might have made us wary of one another, we all instead came together—and an act of terrorism prompted not fright, but compassion and empathy. Those who ran toward the blast on Monday afternoon to aid the wounded, and those who rushed to donate their blood, were but the first to display the spirit, the bravery, and the fraternity of a hurt city.

The unity with which our communities confronted this week’s happenings deserves credit and praise. Police officers, emergency personnel, and the people of Boston have demonstrated incredible resilience and strength—a true cause for celebration.