Despite standing more than 2,500 miles away from the sites of Sept. 11, 2001, Los Angeles has a very tangible connection to the tragedies of that day. Three of the four planes hijacked that Tuesday morning were intended to arrive at Los Angeles International Airport before they were redirected and used as weapons against the World Trade Center and the Pentagon, killing nearly 3,000 people and sparking a decades-long international conflict.

On the 20th anniversary of the attacks, communities across the Southland are holding memorials and ceremonies to honor those killed that day, their families and loved ones, and the first responders who responded to save lives and recover those who were lost.

Waves of Flags

Pepperdine University Alumni Park

24255 Pacific Coast Highway, Malibu

Pepperdine's annual Sept. 11 remembrance ceremony, started in 2008 by students, displays 2,977 flags at the school's Alumni Park — one flag for each person killed in the 2001 attacks.

The events have expanded this year, for the 20th anniversary of Sept. 11, 2001. A silent tribute and remembrance will take place from 5:30 a.m. to 7 a.m. when wreaths will be laid for each of the four airplanes downed that day.

From 8 a.m. to 2 p.m., the victims of all 2,977 victims will be shown on a scrolling display. A prayer service will take place at 9 a.m., and at 9:30 a.m., the film United 93, a dramatization of the attacks, will be screened. At 2 p.m., the day's events will be capped by a ceremony entitled "Honoring the Heroes of 9/11," featuring a keynote speech by actor Gary Sinise. His foundation supports injured veterans and first responders.

For more information, visit pepperdine.edu.

Remembering Sept. 11, 2001 — 20 Years After the Tragedy

Richard Nixon Library & Museum

18001 Yorba Linda Blvd., Yorba Linda

At 11 a.m., the Richard Nixon Foundation will hold a ceremony commemorating the 20th anniversary of the Sept. 11 attacks, including 23 tons of wreckage from the World Trade Center, presented as a "symbol of our national grief and resolve." The ceremony also will include remarks from Orange County elected officials, a formal presentation of the national colors and musical performances.

For more information, visit nixonfoundation.org.

Commemoration of the 20th anniversary of 9/11

Ronald Reagan Presidential Foundation & Institute

40 Presidential Drive, Simi Valley

Starting at 5:30 p.m., the Reagan Foundation is hosting a 20th-anniversary commemoration of Sept. 11 in conjunction with Veterans and Military Business Owners Association and America Salutes You. The event will include keynote remarks by U.S. Army Col. David Sutherland (ret.), retired NYPD officer Marc Manfro and live music.

For more information, visit reaganfoundation.org.

Memorial Pancake Breakfast

El Segundo Fire Department Fire Station 1

314 Main St., El Segundo

The El Segundo Fire Department's annual event honors the victims and first responders of Sept. 11, 2001, from 8:30 to 11:30 a.m. The event will include a remembrance ceremony, as well as family-friendly festivities. ESFD is also hosting free CPR certification courses at 9 and 10 a.m. Proceeds will benefit The Plunge, El Segundo's public swimming facility.

For more information, visit elsegundo.org.

A Celebration of Peace and Unity

Signal Hill Unity Monument

2271 Temple Ave., Signal Hill

The cities of Long Beach and Signal Hill are jointly hosting a "Celebration of Peace and Unity" to mark the 20th anniversary of the Sept. 11 attacks. The event will include guest speakers, an honor guard, musical performance, and more. The event, which begins at 9 a.m., also will be livestreamed on the social media pages of both cities.

The Unity Monument, completed in 2002, represents the United States of America's diversity and faces toward the East Coast in tribute to those lost in the attacks.

For more information, visit cityofsignalhill.org.

9/11 Remembrance Wreath Laying Ceremony

Hermosa Beach 9/11 Memorial

Pier Avenue, between Valley Drive and Ardmore Avenue, Hermosa Beach

The city of Hermosa Beach, with the Hermosa Beach Police Department and LA County Fire Station 100, will hold a remembrance ceremony starting at 9:30 a.m. at the city's 9/11 Memorial. The program includes a presentation of colors, the laying of wreaths and flowers, and a moment of silence.

Annual Remembrance: "We Will Never Forget"

Beverly Hills 9/11 Memorial Garden

445 N. Rexford Drive, Beverly Hills

The city of Beverly Hills will commemorate the 20th anniversary of the Sept. 11 attacks at 5:30 p.m., at the city's 9/11 Memorial Garden. The centerpiece of the garden is a 30-foot bent steel beam, salvaged from the wreckage of the World Trade Center. The garden was dedicated on Sept. 11, 2011, and bears the names of the 2,977 victims of the attacks. A livestream of the remembrance also is available for those who cannot attend in person.

An informal ceremony also will take place at 6:45 a.m. at Beverly Hills Fire Department headquarters, adjacent to the garden.

For more information, click here.

Commemorating 20th anniversary of 9/11

Torrance City Hall

3031 Torrance Blvd., Torrance

The city of Torrance will commemorate the 20th anniversary of the Sept. 11 attacks with a memorial in front of city hall, starting at 5:46 a.m. Speakers will honor the victims, survivors, families and first responders affected by the terror attacks.

The event will be livestreamed on the city's Facebook page.

For more information, visit torranceca.gov.

9/11 20th anniversary Remembrance

Irvine Civic Center

1 Civic Center Plaza, Irvine

The city of Irvine and Team Kids, a local charity sponsoring youth service programs, is inviting residents, families and children to write thank you letters and present them to local firefighters and police officers who will be on site as a way of honoring first responders. Letters also can be submitted virtually via email.

For more information, visit cityofirvine.org.