Harrison originally lived in Starling City and became a well respected yet eccentric scientist and was good friends with equally devoted scientists Tina McGee and Tess Morgan, the latter of whom he fell in love with and eventually married. The original timeline, Wells and Morgan successfully built S.T.A.R. Labs and the particle accelerator which resulted in Barry Allen becoming the Flash in 2020.
In 2000 in the current timeline, Harrison was planning on opening a laboratory in Central City, talking with Tess about this while Eobard Thawne watched over from a distance. As Wells drove with Tess, Eobard left spike strips across the road, causing them to crash their car. Wells' life was then ended when Eobard uses a strange device that transferred Wells' likeness into Eobard while completely dissolving Wells into a decayed corpse in a matter of moments. Eobard killed him and took Wells' identity in order to get back his own timeline.[1]
Although Harrison and Tess never got the chance to start nor see S.T.A.R. Labs, their company and the particle accelerator still exist in the alternate timeline because of Eobard Thawne, under the guise of Harrison, using his knowledge of the future to create and activate the particle accelerator.
It wasn't until the years 2015 when Joe West and Cisco Ramon later discover the real Harrison Wells' corpse near the crash site in Starling City after Barry learns from McGee that Wells was a completely different person after Morgan's death. After some tests, they ascertained that the decayed figure was the true Wells, meaning their mentor was an impostor.[2]