COMMUTERS slid to work after roads and footpaths were turned into lethal ice rinks by the freezing rain.
Police and firefighters warned South Yorkshire residents to take extreme care as black ice covered the county.
Motorists struggled to get off estates and many routes into the city were blocked by minor shunts.
Up to 40 collisions have already been reported.
Hospital bosses said they had been inundated with casualties who had slipped on the ice.
By 11.30am staff at the Northern General Hospital said more than 70 people had been brought in with fall-related injuries.
A hospital spokesman said: “All of Sheffield’s adult hospitals are running services as normal and patients should still attend for their outpatient appointment, surgery or treatment as planned today unless they are likely to put themselves at risk of a fall by venturing out.
“If anyone cannot attend their appointment please contact the hospital using the number on their appointment letter and arrangements will be made to reschedule the appointment. “We are also aware there is severe disruption to the non-urgent patient ambulance transport which picks up some patients to come to outpatient appointments.
“This is due to the increased volume of emergency ambulance calls to which the Ambulance Service needs to give priority.
He added: “People with non-urgent minor injuries or illnesses are also being asked not to visit the A&E department at the Northern General and instead asked to seek advice or treatment from their local pharmacist, GP or the NHS Walk in Centre on Broad Lane.
“This will enable A&E staff to concentrate all their efforts on the sickest and most urgent patients who are in need of emergency care today.
Weather experts said the problem was caused by so-called ‘freezing rain’ - when the rain freezes on impact, covering surfaces with ice.
But they say the situation should ease as the ice thaws.
Many schools were closed this morning while others were due to open late.
Bus services were also affected.
One of the worst incidents was a five-vehicle smash involving a fire engine and paramedic car on Barnsley Road at Sheffield Lane Top.
A Vauxhall Vectra skidded into a tree at around 4am and firefighters from Elm Lane station, who were called out to deal with the incident crashed into the Vectra - crushing it into the tree even further. The tree had to be felled.
A paramedic fast response car crashed into the lampost bending it in two, and two vehicles which took evasive action also crashed.
Police cordoned off the road and roads around Stubbin Lane were cordoned off following the incident.
A man was taken to hospital with serious injuries after his pick-up truck ran out of control on Brecks Crescent, Listerdale, Rotherham, and ended up crashing through a garden wall.
He managed to get out of his vehicle but then a van skidded on the same patch of ice and crashed into the pick-up truck driver.
The A628 Woodhead Pass was partially blocked between Glossop turn off in High Peak and Dunford Bridge turn off in Dunford Bridge, because of ice and an accident involving a lorry and three cars.
Meanwhile at 4.45am this morning a lorry skidded on the ice and crashed into Tankersley fire station.
A fire service spokeswoman said the lorry driver was shaken but otherwise unharmed.
A bus was involved in a smash on Foxhill Road near Foxhill Drive and there were other collisions on Retford Road at Woodhouse Mill, Sheffield; West Close, Kimberworth, Rotherham; Millhouses Street, Hoyland; Stannington Road, Twentywell Road, Bradway and Green Lane, Wath, Stannington Road, Stannington.
Also closed were Westhill Road, Rotherham, Gilbert Hill, Stocksbridge, Woodhead Lane, Blacker Hill, Barnsley, Thrybergh Lane, Rotherham,
Police said several cars had slid down Whitehouse Lane, in Walkley, Sheffield.
Amey, the contractors in charge of gritting in Sheffield, told The Star they were out gritting roads from 7.30pm last night.
But the freak weather conditions still caused treacherous conditions this morning.
Wayne Southall, of Amey, said: “Gritters have been out over night and they are out again this morning.
“We expect the ice to thaw by mid morning, but we are gritting just in case.
“The problem is this so-called freezing rain. Some pavements are also very icy and people are walking in the roads, but that brings its own problems.”
A spokesman from Sheffield Council’s Streets Ahead team said: “Black ice has formed throughout the night making conditions across the city difficult despite the gritting team of 20 gritters spreading a total of 200 tons of salt on the priority network roads last night. “First thing this morning we sent the full fleet of gritters back out and we are doing everything we can to help people get to work this morning.
“We are salting city centre key pedestrian routes and pavements around the hospitals.
“We are encouraging all travellers to take extra care whilst travelling, plan their journeys in advance and as ever exercise caution on all roads and side roads, especially on pavements, and to try to travel on major roads wherever possible.
“As ever we will keep a close eye on the weather to make sure we respond appropriately, and will use all the equipment at our disposal to ensure safety across the city.”
A Barnsley Council spokeswoman said gritters were out across the borough last night and started again at 3.30am this morning.
He said: “With regards to footpaths, officers have been out since first thing this morning, gritting in accordance with the council’s snow plan.
“The plan covers local shopping areas including Barnsley town centre, outside doctors’ surgeries and schools, OAP sheltered housing complexes and OAP bungalow estates.
“The snow plan is a reflection of local priorities agreed through a consultation process at Ward Panel meetings with local ward councillors and members of the public and covers over 400 sites.
“Once these have been dealt with the teams will then move onto other locations and specific requests.
Freezing rain occurs very rarely in this country.
It falls on already frozen surfaces and the ground appears wet but it is actually covered in a layer of ice up to a centimetre thick.
*How have you been affected this morning? How was your journey to work? Tweet us @SheffieldStar, put a message on our Facebook site www.facebook.com/sheffieldstar or email email@example.com
For updates see www.sheffield.gov.uk/winter or follow Streets Ahead on twitter @sccstreetsahead
For a list of grit bin locations and for full priority gritting routes visit https://www.sheffield.gov.uk/gritting
Open late: Treeton C of E Primary School, Windmill Hill Primary, Chapeltown; Tinsley Nursery and Infant School; Stocksbridge Nursery and Infant School and St Patrick’s Catholic Primary School, Shafton ALC, Barlow C of E Primary.
Matlock All Saints’ CE Infant School - open at noon and kids should bring a packed lunch.
Barlow C of E Primary - open at 10.30am
Eckington Junior School - open at 10am this morning.
Brimmington Junior School open at 10.30am
Hady Primary School - open until 10am
Gilbert Heathcote Nursery and Infant School - open at 10am
Closed: Hasland Hall Community School, Eckington Junior School, Unstone Junior School, Westfield Infant School, Carlton Community College, St Helen’s, Hoyland, Cherrydale, Cudworth, Talbot Special School and Woolley Wood School, The Brigg Infant School.
Rotherham residents are being warned that bin collection schedules could be delayed today because of this morning’s bad weather.
Rotherham Borough Council’s 32 tonne waste collection vehicles are experiencing major difficulties on side roads and footpaths and today’s collections might have to be completed tomorrow.
Outstanding black bins due to be collected today will be collected on Saturday, while any outstanding green bins and blue boxes will be collected next week if they are not picked up today.
The authority apologises for any disruption in service but waste crews have to be mindful of health and safety issues when driving large vehicles in bad weather conditions.