POLAND, Maine (AP)   A Maine couple is installing a “ghost bike” memorial at the site where their son was killed by a drunken driver 20 years ago.

Bob Barton says he learned about ghost bike memorials online, and says he thinks this will be the first monument of its kind in the state of Maine. The Sun-Journal reports Bob and Suzanne Barton will place the memorial and a plaque next week to commemorate the 20th anniversary of 16-year-old Ethan Barton’s death.

The Barton couple will place the white-painted bike at the site where Ethan was killed in Poland.

In 1998, Ethan was struck and killed by Gale Chapman, whose blood alcohol level was measured at three times the legal limit. Chapman served 18 months in prison and later killed herself in 2015.