An employee at the Lethabo Power Station in the Free State died and another was seriously injured in a “major incident” on Wednesday afternoon, Eskom said.

The power utility said in a statement that police officials were on the scene at Unit 5 and emergency response teams had been activated.

“The Department of Labour has been notified and Eskom executives are travelling to the site… As a result of the rupture of a mainsteam pipe, the unit is not operational. Operations continue on the other units.”

Energy expert Chris Yelland tweeted that there had been a boiler explosion.

Eskom confirms only Unit 5 at Lethabo is down after a generator trip followed by a loud boiler explosion. The other 5 units at @Eskom_SA‘s Lethabo PS are still operating, but staff have been evacuated as much as possible as a precautionary measure. Situation “calm” at the moment.

— Chris Yelland (@chrisyelland) October 10, 2018

What’s going on at #eskom? Fire again. It was very easy for #ThumaMina to destroy the technical excellence we put together over many years. It’s becoming a mission impossible to rebuild. Indeed Eskom can’t save itself pic.twitter.com/yOhYgzpbb1

— Matshela Koko (@koko_matshela) October 10, 2018

Eskom Lethabo Power Station, boiler explosion 61 meter level at unit 5. #NewsUpdate #eNCA pic.twitter.com/T3T6MfBn8i

— D?King (@IM_KING_Dee) October 10, 2018