(Meredith) -- A transformer fire at an electrical substation in Puerto Rico has knocked out power across the island.
Utility company Luma Energy said they're working to restore the system, and work will continue overnight.
Puerto Rico's governor called it an explosion, and said state and federal law enforcement authorities are investigating the cause.
Luma Energy said it was hit by a cyberattack earlier in the day.
It was a "distributed denial of service" attack, in which a site is deliberately hit by massive amounts of web traffic to try and overwhelm it.
There's no immediate indication of any connection between the website attack and the substation incident.