The National Portrait Gallery is closed for a day following an unexpected power outage, according to reports. The gallery announces the temporary closure as a response to the electrical disruption, with staff arranging for checks and recovery work before reopening. The outage is described as unexpected by the outlets covering the incident, and the closure is presented as a short-term measure rather than a wider emergency. No details are provided in the supplied reports about the cause of the outage, when it occurred, or whether specific areas of the museum were affected. The available information focuses on the decision to close the gallery for a day and implies operational steps are required before normal opening resumes. Viewers and visitors are advised to expect the closure on the scheduled date, reflecting the gallery’s need to ensure conditions are safe and fully operational after the incident.