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 24-year-old man has been jailed after his careless driving killed four members of the same family.
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.
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.