The Arthur Ravenel Jr. Bridge across the Cooper River opened on July 16, 2005, and was the second-longest cable-stayed bridge in the Americas at the time of its construction.[citation needed] The bridge links Mount Pleasant with downtown Charleston, and has eight lanes plus a 12-foot lane shared by pedestrians and bicycles. It replaced the Grace Memorial Bridge (built in 1929) and the Silas N. Pearman Bridge (built in 1966). They were considered two of the more dangerous bridges in America and were demolished after the Ravenel Bridge opened.
If it is possible to answer this question, answer it for me (else, reply "unanswerable"): What year was the Grace Memorial Bridge built?
1929