Updated: 2:06 p.m. Capitol Police and D.C. fire officials have determined that an alarm at the Capitol Visitor Center was set off by construction work on the newly opened building. Police will soon reopen the building, after evacuating staffers and visitors at about 1 p.m. on Friday. Some welding appears to have either produced a spark or some smoke, setting off the CVC’s audible alarm, said Capitol Police spokeswoman Sgt. Kimberly Schneider. It isn’t uncommon, she said — similar evacuations have occurred in other Congressional buildings. The CVC has been open for less than two weeks. Its construction was plagued with criticism for being behind schedule and over budget. At $621 million, it has a footprint bigger than the Capitol and state-of-the-art security systems.