Power is gradually being turned back on across parts of South Australia, but much of the state remains in darkness after a widespread blackout.
But more wild weather is on the way, with an intense low-pressure system expected to cross the state today.
Late on Wednesday, emergency services had announced the following:
* Power is continuing to be restored overnight. Metro areas will be first
* People in the state's north are likely to be without power for "considerably longer than the rest of the state"
* There are no reports of deaths or serious injury
* Adelaide Metro trains are expected to be running from Thursday morning
* All schools in the state will be open, but some still without power may have different programs
Bureau of Meteorology senior forecaster Brett Gage said a severe weather warning remained current for widespread parts of the state, with the west coast of Eyre Peninsula in for a "real buffeting".
Winds in that region are expected to reach storm force, with predicted gusts of up to 140 kilometres per hour.
"Gale force [winds] about the remainder of the coasts, except for the two South East coasts where we do have strong wind warnings current," he said.
A flood watch is in place for the state's Mid North, Mount Lofty Ranges and Adelaide with rain of 30mm to 60mm expected to hit, with some falls of 50mm to 100mm possible.
SA Power Networks spokesman Paul Roberts said power was being restored to some of Adelaide on Wednesday evening, but warned it would be a "gradual process".
He said people in the Mid North and Eyre Peninsula areas should prepare for extended power outages.
"That could well go into the the early hours of [Thursday] if not longer. This would be putting some stress on communications and I really recommend to people they minimise their use of mobile phones."
The statewide outage happened after severe weather knocked out three transmission lines and 22 towers.
Mr Roberts said the storm front expected on Thursday is a big concern for the electricity network.
Optus and some Vodafone networks are also down across the state.
Mr Roberts said some equipment had been damaged around Blyth in the state's Mid North.
"There was some kind of mini-storm event, or cyclone event, there that's resulted in damage and that's affecting customers around the region.
"We have a substation there that would supply out to several areas."
Town takes a beating from storm
David Williams, from Blyth, said his town had taken a "beating".
"Basically it blew the veranda up over the top and took part of the roof and the chimneys … [there was] lots of noise. It was a bit scary," Mr Williams said.
He said he huddled in the kitchen as the wild wind passed over his home.
Mr Williams described the noise as "like a freight train".
"There's a lot of people without roofs tonight. It's taken a beating [Blyth]. It's not feeling too well. There's a fair few people hurting tonight."
The Country Fire Service (CFS) has sent a strike team to Blyth. The extent of damage is unknown at this stage.
Police have urged owners and occupiers of buildings to check if anyone is trapped in lifts after emergency services rescued 19 people from lifts.
Emergency services have already rescued a number of people who became trapped when the power shut down.
Earlier, Telstra's SA general manager spokesman Mark Bolton said mobile phone users should prepare for a loss of network coverage as towers and exchanges ran out of back-up power.
"We have had a few sites that have been identified as down, yes, so there are a few sites that are failing and probably more to come as the power outage is extended," Mr Bolton said.
Lightning takes out generators
Premier Jay Weatherill said there had been 80,000 lightning strikes across the state.
"Some of them hit our electricity infrastructure including our generators. This is making the job of turning the power back on extremely hazardous and difficult."
He urged people not to travel on the roads "unless absolutely necessary" during the blackout.
Mr Weatherill said the weather event had "destructive wind gusts" which saw transmission poles pulled out of the ground.
"The count is 22 and climbing," he said.
Earlier in the day, he said there was an incident about 3:48pm "which has caused the failure of the entire South Australian electricity network".
He said the blackout had nothing to do with the recent closure of the Port Augusta power station.
"The system has behaved as it's meant to behave to protect the national energy market," Mr Weatherill said.
He said the statewide blackout occurred due to the massive damage to infrastructure which resulted in the sudden drop in energy frequency in the network. It triggered an automatic cut at the interconnector to protect the national network.
Federal Energy Minister Josh Frydenberg said the Australian Energy Market Operator, which was responsible for the management of the National Electricity Market, was working closely with the relevant transmission network service provider, ElectraNet, to identify and understand the severity of the fault.
South Australian Senator Nick Xenophon told ABC News 24 that he understood power would not be restored to South Australia until 4:15am on Thursday.
"This is how not to do [transition to renewables]. I can't fathom ... I can't believe my state is in darkness at the moment. If heads have to roll, so be it," he said.
"We're looking at another 11 hours of darkness, and the consequences of that are just horrendous."
'Extreme demand' for emergency services
South Australian Police Commissioner Grant Stevens has declared the statewide power outage a major incident under the Emergency Management Act.
"We are confident that all of the emergency services and support agencies have sufficient resources," he said.
SA Ambulance chief executive Jason Killens has urged South Australians to only call 000 for genuine emergencies.
"We are currently experiencing extreme demand as a result of the weather event," he said.
"As a result we are dealing with a significant increase in emergency calls."
All train and tram services have stopped for safety reasons, with Adelaide Town Hall staying open to accommodate anyone who cannot get home.
SA Water said it had lost power to some of its pumping stations which was affecting its ability to deliver water and remove sewage to some customers.
Adelaide Airport said power had been restored but it was experiencing issues with its baggage system.
- ABC