Residents of Washington, D.C., and 19 other nearby metropolitan jurisdictions will receive test text notifications next week as part of an automatic National Wireless Emergency Alerts System test. The system allows government officials to send emergency alerts to specific geographic areas on cellphones or other mobile devices. People in the 20 participating jurisdictions will receive the following message on Thursday, April 5: “A test of the District of Columbia Wireless Emergency Alerts System. No action required.” The alert is expected to be accompanied by a loud noise as it displays the message. Residents of Washington, D.C., and 19 other nearby...