Under a warm winter sun, people across the East Bay marched, sang and worked as volunteers to clean up the shoreline Monday, the day the nation sets aside to remember the legacy of Martin Luther King Jr.

"Injustice anywhere is a threat to justice everywhere," words written by King in a 1963 letter from the Birmingham, Ala., jail, where he spent eight days after being arrested for protesting, were printed on a sign held by Castro Valley resident Billy Bradford at a parade in downtown Hayward.

"We're celebrating Martin Luther King Jr.'s legacy on a day when our president is being sworn in for a second term, and he's using King's Bible. This is a powerful day," said Bradford, who was representing Castro Valley Pride and the lesbian, gay, bisexual and transgender community. "I know that if Martin Luther King Jr. were alive, he would be standing with his LGBT comrades in support of marriage equality."

In Oakland, volunteers converged on the park that bears the civil rights leader's name to restore wildlife habitat. While volunteer crews planted native vegetation and picked up trash from Arrowhead Marsh in Martin Luther King Jr. Shoreline Park, near the Oakland airport, Golden Gate Audubon docents led bird walks highlighting the local wildlife -- including endangered California clapper rails -- that benefit from the volunteers' work.

Before the Hayward march, which began at City Hall, performers were featured, including youth choirs from First Tongan United Methodist Church of San Bruno and First United Methodist Church of Hayward, the musical group Gravity Plus 2 and members of Congregation Shir Amir of Castro Valley.

Some marchers broke out in song as the group of about 150 walked through downtown. Members of the Hayward Tongan youth choir sang "We Are Marching in the Light of God," their voices resonating off buildings as they walked down Mission Boulevard.

It was the 10th year for the march and rally sponsored by South Hayward Parish. Organizer Dr. Roy King Jr., a psychiatrist who is an intern minister at Starr King Unitarian Universalist Church in Hayward, said the day was profoundly significant for him as an African-American and budding minister.

"It raises our consciousness and focuses me on what's essential in the ministry, which is bringing justice to the world," he said.

Hayward's march was the third one for Victoria Geter, 12, of San Leandro, who was holding a sign that read "Liberty and justice for all." She said the civil rights leader is her idol.

"I want to be like Martin Luther King," she said. "I want to be a public speaker to show little children what's right and wrong."