After losing her longtime boyfriend, firefighter Michael Kennedy, in the deadly nine-alarm blaze in the Back Bay last month, Sarah Wessmann is running the Boston Marathon in his memory, WHDH reports.

Both were at the finish line last year, Sarah as a spectator one block from the second bomb, Mike as a first responder who came running from his firehouse to help a woman who would lose her leg.

This undated photo released by the Boston Fire Department via Twitter shows firefighter Michael R. Kennedy, killed Wednesday, March 26, 2014, when trapped the basement while fighting a fire in an apartment building in Boston. Kennedy, 33, a Marine Corps combat veteran was assigned to Ladder 15, and had been a firefighter for more than six years. (AP Photo/Boston Fire Department)
Michael R. Kennedy
AP/Boston Fire Department

After last year’s bombings, Wessmann and Kennedy planned to run the Marathon together this year. Kennedy previously ran the Marathon in 2009, where he painted Wessmann’s initials on his calf. At that time Wessmann cheered him on from the sidelines.

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This year, will be Wessmann’s first Marathon and she’ll run all 26.2 miles with Kennedy’s initials on her calf.

Kennedy’s mother, Kathy Crosby-Bell, previously told The Boston Globe, that she wanted Wessmann to also wear his number.

"They were training together," his mother said. "I asked Sarah if she would take Michael's number and run it for both of them, and give me his number afterward. My heart aches for this girl."

So, Wessmann will also wear Kennedy’s bib number, 29384, on Monday.

"[The marathon] meant a lot to me before but now it means double. But it meant a lot to me just running," she said.

On Monday, Kennedy’s friends will be cheering Wessmann on at the finish line. All are helping raise money for the family of Lieutenant Edward J. Walsh Jr., 43, of West Roxbury, who was also killed in last month’s deadly fire.

(H/T WHDH)