NEW YORK (AP) — Holding photos and reading names of loved ones lost 16 years ago, 9/11 victims’ relatives marked the anniversary of the attacks at ground zero on Monday with a solemn and personal ceremony.

Every Sept. 11 since the date of the deadliest terror attack on American soil, Rob Fazio has come to the place where his father, Ronald Carl Fazio, and thousands of others died.

“I’ll come every year for the rest of my life,” the son said. “It’s where I get my strength.”

At least 1,000 family members, survivors, rescuers and officials were gathered as the ceremony at the World Trade Center began with a moment of silence and tolling bells. Then, relatives began reading out the names of the nearly 3,000 people killed when terrorist-piloted planes hit the trade center, the Pentagon and a Pennsylvania field, hurling America into a new consciousness of the threat of global terrorism.

Some said they couldn’t believe 16 years had passed since a tragedy that “still feels like yesterday,” as Corina La Touche put it as she honored her father, Jeffrey La Touche.

To others, it was an occasion to thank first responders and members of the military, to express concern for those affected by Hurricane Irma as it continued its destructive path as a tropical storm, or to plead for a return to the sense of unity they felt after the attacks.

“Our country came together that day. And it did not matter what color you were, or where you were from,” said a tearful Magaly Lemagne, who lost her brother, Port Authority of New York and New Jersey Police Officer David Lemagne. She implored people to “stop for a moment and remember all the people who gave their lives that day.

“Maybe then we can put away our disagreements and become one country again.”

Added Michael Buhse, who lost his brother, Patrick: “We will never forget — and we will never forgive.”

Sixteen years later, the quiet rhythms of commemoration have become customs: a recitation of all the names of the dead, moments of silence and tolling bells, and two powerful light beams that shine through the night.

Yet each ceremony also takes on personal touches. Some name-readers added messages ranging from the universal to the personal — updates on family graduations and marriages, memories of personality traits and favorite foods.

Some have never even had a chance to meet the relatives they lost on Sept. 11, 2001.

President Donald Trump, a native New Yorker observing the anniversary for the first time as the nation’s leader, said the nation grieves for the people “who were murdered by terrorists” 16 years ago.

Speaking at an observance at the Pentagon, the Republican president issued a warning to extremists, saying “America cannot be intimidated.”

When America is united, “no force on earth can break us apart,” he said.

Vice President Mike Pence and U.S. Secretary of the Interior Ryan Zinke were scheduled to deliver remarks at the Flight 93 National Memorial near Shanksville, Pennsylvania. It’s on the field where one of the airliners crashed after passengers and crew fought to wrest control away from the terrorists who’d hijacked it and were heading for Washington.