Here's how 7 US cities still remember 9/11, 25 years later

The Tribute of Light in Manhattan is one of several September 11 ceremonies held in New York City.

Bloomberg/Getty Images This year marks the 25th anniversary of the September 11, 2001, terrorist attacks.

Cities across the US have found ways to commemorate the attacks and those affected by them.

New York City has the Ground Zero ceremony, but there are traditions from coast-to-coast.

Today is the 25th anniversary of September 11, 2001, when terrorists hijacked four commercial passenger planes , crashing two into New York's Twin Towers and killing 2,977 people.

Another plane hit the Pentagon in Arlington County, Virginia, and the fourth plane crashed into a field in Shanksville, Pennsylvania, after the passengers on board attempted to retake the cockpit and overcome the hijackers.

Since the attacks, the US has created over 1,100 memorials across all 50 states where visitors can reflect and honor those who died.

Communities have also developed traditions and ceremonies to mark the anniversary.

Visitor numbers can vary depending on how the community is connected to the attacks.

From stair climbs and gun salutes to walks of remembrance and observances, here are ways US cities have commemorated the attacks.

New York City A person puts their hand on a picture of Father Mychal Judge at the 9/11 Memorial in NYC on the 25th anniversary.

Jeenah Moon - Pool/Getty Images New York City's skyline fundamentally changed following the attacks.

Twenty-three New York Police Department members died in the line of duty , and hundreds of NYPD officers have died as a result of 9/11-related illnesses.

The 9/11 Memorial & Museum, located at the World Trade Center in Lower Manhattan, is the heart of the nation's 9/11 ceremonies.