A one-block section of First Street from College to Main street will close for at least one year while work proceeds on the Multi-Purpose Events Center being built by Montgomery County. Construction officials said the closure of First Street was necessary to support construction activities as the project moves into its next phase. Signs and barricades are placed on the street. “In the next month our crane and steel operations will pick up, and some more underground utility work will begin,” said John Yunker, construction supervisor for Skanska USA, the project’s construction management company. “It’s the absolute best option to close the street and create a construction zone because of all the activity we will be seeing.”