BELLINGHAM, Wash. -

Officials say a high school near the Canadian border will remain closed for an undetermined length of time after an electrical explosion caused damage and briefly knocked out power to 600 customers.
   
The Bellingham Herald reports the blast happened Wednesday night, closing all Blaine public schools on Thursday.
   
Authorities say no one was injured and the cause of the blast remains unknown.
   
North Whatcom Fire and Rescue Division Chief Henry Hollander says the incident occurred in a mechanical room with electrical breakers and equipment for the building's fire-suppression system and district-wide internet services.
   
Power and communications systems, including phone and internet services, were restored to the other schools Thursday, allowing them to open Friday.
   
Hollander says structural and electrical engineers and insurance adjusters have been evaluating damage.