Near the marathon's finish line on Monday, runners and spectators may notice two rounded sidewalk extensions of red brick and granite gently bulging into Boylston Street.
They're part of a memorial in progress to the lives lost in the 2013 Boston Marathon bombing. Artist Pablo Eduardo has been designing the memorial, in collaboration with the families of the three people who died at the sites — Lingzi Lu, Martin Richard and Krystle Campbell. It is scheduled to be finished later this summer.
When the memorial is finished, three standing granite markers will honor Lu, Richard and Campbell, and two bronze markers within the red brick will honor the police officers who died after the attacks: MIT's Sean Collier and Boston's Dennis Simmonds.
The two sites will also each have four slender 21-foot spires; on the outside of the spires will be twisting strands of hammered bronze.
"Inside of them, there is cast glass that will light up," said Eduardo at the Chelsea foundry, where he's been working on the memorial. "That's all to signify how fragile our life and our ideas are — all those things are represented in the glass, and it's really, really well protected by these columns of bronze."

Dixie Patterson has been following the memorial plans. She's a physician's assistant, and a runner herself, who's been volunteering at the finish line medical tent for years now. That made her a first responder in 2013.
"I'm very happy about the memorial," Patterson said. "A lot of us like to say, 'You know what, these are the good things that we're focusing on that have happened since the bombing.' I think that's hopefully what the memorial will accomplish as well: to have a good positive vibe."
Pablo Eduardo says a poet from Boston provided the words inscribed on large brass circles to be installed in the ground at the memorial.
"He gave us two phrases to put in the circles, one on each, Eduardo said. "'Let us climb now the road to hope.' is one. And, 'All we have lost is brightly lost.'"
Rebekah Gregory and her son were three feet away from one of the bombs on April 15, 2013. They both survived; she lost her left leg. She said the memorials will be inspiring on many levels.

"The idea of it is ... lives were changed forever — and many people were — but we're not broken," Gregory said. "The light from each of [the spires] reminds us of the good that's still out there; and it also reminds us that we want to be part of that good."
Gregory said it's important that Eduardo has been working closely with the families of those who died, and she said those families' determination in the face of their loss is the true definition of 'Boston Strong.'