This isn't your average old wreck though. It was the first chapel built by London's black community, mainly fugitive slaves who arrived via the Underground Railroad. It was originally named the African Methodist Episcopal Church and was later renamed the British Methodist Episcopal Church.
Abolitionist John Brown probably spoke here in 1858, appealing for funds to fight slavery in the United States. In all probability, Brown's plan was to form a black military company which would join other black fighting units from Ontario to bring about his proposed abolitionist revolution. The following year, his raid on Harpers Ferry acted as a catalyst in bringing about the American Civil War.
Eventually, London's black community founded another church on Grey Street and 275 Thames Street became a residence. In August 1986, an historic plaque was placed on the building by the London Public Library Board. The plaque has since gone missing and it's thought that former owners took it with them when they moved.
Londoners, and Canadians in general, should be proud of Canada's role as sanctuary for fugitive slaves during the years before the Civil War. This is not a building to be lost. Somehow, a solution must be found.
Update, September 2015: Well, they did it. In November 2014 the very determined folks at The Fugitive Slave Chapel Preservation Project moved the old building to sit beside its daughter church at 432 Grey Street. Now the real challenge begins as the committee raises funds to restore the building. See here for more details.
Update, October 2015: Architect John Rutledge of Blyth has been hired by the FSCPP to restore the building for museum purposes. If all goes well, this will turn into one of London's best examples of adaptive reuse.
Update, January 2021: All did not go well. The committee fell apart and the project stalled. Conflicting rumours about whose "fault" this is. Meanwhile, the building sits, wrapped in plastic and controversy, awaiting refurbishment.