A 68-year-old man apparently received an electrical shock at Punahou School about noon Wednesday.
Emergency Medical Services officials reported his condition to be serious, and said he fell from a ladder after the electrical shock.
A spokeswoman for the school said in a written e-mail that the man was a school electrician involved in an electrical accident.
The man was taken to the hospital where he was being treated and held for observation.
The school is looking into the circumstances of the accident, but did not release any further details.
“Our priority at this time is the well-being of our employee,” the school said.