BOSTON (CBS) — Thousands of American flags are filling the Boston Common ahead of Memorial Day to honor Massachusetts’ fallen heroes.

In a special ceremony on Thursday morning, 219 flags will be added to the tribute, each one representing a Massachusetts man or woman who has died serving their country since the 9/11 terrorist attacks. Gov. Charlie Baker and Boston Mayor Marty Walsh will be speak at the ceremony where the names will be read aloud.

American flags on Boston Common (WBZ-TV)

American flags on Boston Common (WBZ-TV)

More than 600 volunteers gathered on Wednesday to start planting the 8 x 12 flags in the ground. Others are volunteering to watch over the flags throughout the weekend.

In total, 37,000 flags will be placed on the Common.