Johannesburg - Two men sustained severe burns while working on an electrical transformer at a university in Roodepoort on Sunday night, Netcare 911 said.
One man sustained 50% burns and the other 20% burns when a ''flash over'' - a burst of very high energy - occurred.
Netcare 911 spokesperson Chris Botha said the men had to be stabilised on the scene before one of them was taken to hospital by helicopter, and the other by ambulance.