BOSTON (CBS) — As the Massachusetts Senate prepares to debate a bill that would expand rights for transgender people next week, Mayor Marty Walsh raised a flag celebrating transgender equality over Boston City Hall.

Proud to fly the #TransFlag over Boston City Hall for the 1st time in MA history – a sign that everyone is welcome. pic.twitter.com/Nwpm8lAeJo — Mayor Marty Walsh (@marty_walsh) May 2, 2016

Walsh pointed out that Boston has had transgender protections in place since 2004.

“It’s long past time for us to put some protection in place across our state,” Walsh said. “I don’t want our state to fall behind on this.”

Other city and state leaders, including Mass. Senate President Stan Rosenberg, State Senator Sonia Chang-Diaz, Representative Denise Provost, and City Council President Michelle Wu, joined Walsh Monday afternoon in the rain on City Hall Plaza to raise the flag.

Boston is only the fourth municipality in the country to fly the transgender flag, and the first in the state to do so.

According to a release from Freedom Massachusetts, the flag, which consists of blue, pink, and white stripes, was designed by transgender Navy veteran Monica Helms in 1999.

Helms has said that the pink and blue stripes represent traditional colors for boys and girls, while the white stripe represents “those who are intersex, transitioning, or consider themselves having a neutral or undefined gender.”

Grace Sterling Stowell, a transgender woman who works with young people, said protections are badly needed.

“The children and young people of our communities, especially youth of color, are the most at risk for discrimination and violence directed at them simply for being who they are,” said Stowell.

Senate President Stan Rosenberg said the flag was raised “because it is the right thing to do, and we will also send a message that we are open for business here in Massachusetts.”

Rosenberg said the Senate is expected to debate the transgender bill on May 12.

WBZ NewsRadio 1030’s Ben Parker reports