The A470 is closed in both directions after an accident between B4518 (Llanidloes) and A489 Long Length (Caersws). Police are directing traffic.
Llanidloes Graham Davies ward at Llanidloes hospital in Powys has closed to new admissions and to all visitors due to a possible diarrhoea or vomiting bug.
The ward will stay closed until no patients have any symptoms.
A spokesperson from Powys teaching Health Board said, "It is particularly important that people who are unwell keep away from patients in hospitals and long-term care facilities as they may be at increased risk of contracting gastroenteritis.
"If they do contract it they may experience more severe symptoms and it may exacerbate their other health problems."
"It is important that, if patients being admitted to hospital, or their household contacts, have been suffering from gastroenteritis within the last 48 hours, they should inform the admitting doctor."
Denise Griffith has made a statement following the sentencing of Gordon Dyche.
24-year-old Dyche was jailed after his careless driving caused a crash that killed four members of Mrs Griffith's family.
Through a family liaison officer, Mrs Griffith thanked those who have assisted her during 'the worst time of her life'.
A 24-year-old man has been jailed after his careless driving killed four members of the same family.Read the full story ›
A 24-year-old man has been jailed for four years after his careless driving killed four members of the same family.
Gordon Dyche, of Llanbrynmair in Powys, was driving near the Llyn Clywedog reservoir last year when his car clipped the family's people-carrier.
The vehicle, driven by Denise Griffith, plunged into the water. She survived but her mother, husband and two foster sons died.
Dyche, who denied the charge, will be banned from driving for a further four years on his release from prison.
A man accused of causing the deaths of four people by dangerous driving told police he was satisfied it had been safe to overtake two cars.Read the full story ›
A man accused of causing the deaths of three generations of one family by dangerous driving said: "I was being stupid; I was late for work" as he looked for survivors of the crash.
Witness James Denham was giving evidence at the trial of mechanic Gordon Dyche of Ffordd y Coedwyr, Llanbrynmair.
Mr Dyche denies four charges of causing death by dangerous driving and four charges of causing death by careless driving.
The prosecution alleges it was his impatient driving which caused the deaths of Emyr Griffith, Phyllis Hooper and foster children Peter Briscombe and Liam Govier in April last year.
James Denham was a passenger in the car which Gordon Dyche had overtaken. He described how the car in which the family was travelling had indicated to turn right into a lay-by at the side of the reservoir. Mr Dyche's car hit it as he tried to overtake both cars.
The family's car had rolled over, hit a fence and disappeared into Llyn Clywedog after being hit by Gordon Dyche's vehicle.
Only Denise Griffiths, who was driving the family's Peugot car, and the family's pet dog survived. The trial continues.
A man from Powys has gone on trial accused of causing the deaths of four people whose car went into a reservoir in mid-Wales last April.Read the full story ›