A 55-year-old man received head and neck injuries when he fell into a power-line ditch on Sussex Rd, Hastings, yesterday afternoon.
The man was contracted by Unison networks and was excavating a ditch, converting overhead lines underground about 4pm, when he toppled backwards into the trench.
A St Johns Ambulance spokesman said ambulance staff treated him for head and neck injuries before taking him to Hawke's Bay Hospital.
Unison customer-relations officer Danny Gough said yesterday details of the workplace accident were still unclear but his colleagues were hoping his injuries were not too serious.
"It's not clear exactly how he came to end up in the ditch. Two chaps were working on the site and filling a trench," he said. "One of the men went to move the work truck and, after returning to the ditch, found his workmate lying in the ditch, it appears he has fallen backwards - he was in a significant amount of pain but was conscious."
Mr Gough said safety was paramount for Unison and an internal and formal investigation would take place.
A hospital spokeswoman said the man was in a serious but stable condition last night.