A haulage boss and a mechanic have been convicted of manslaughter after a 32-tonne truck with faulty brakes killed four people.
Matthew Gordon, 30, and Peter Wood, 55, were each convicted of four counts of manslaughter following a trial at Bristol Crown Court.
Phillip Potter, 20, the driver of the truck which hit Mitzi Steady, four, Robert Parker, 59, Philip Allen, 52, and Stephen Vaughan, 34, was cleared of all the charges he faced.
The victims were struck by the heavily-loaded Scania truck carrying aggregate down Lansdown Lane in Upper Weston, Bath, on February 9 last year.
Trial judge Mr Justice Langstaff remanded Gordon and Wood in custody and said he would pass sentence on January 27.
Gordon, of Dauntsey, Wiltshire, and Wood, of Brinkworth, Wiltshire, showed no emotion as the jury forewoman returned the four verdicts.
The panel cleared Potter, also of Dauntsey, of causing death by dangerous driving, causing death by careless driving and causing serious injuries to Karla Brennan and Margaret Rogers by dangerous driving.
During the trial, the court heard that Potter was following Gordon, the owner of Wiltshire-based Grittenham Haulage, down the steep lane when the brakes on his 11-year-old truck failed.
He struck Mitzi and her grandmother Mrs Rogers as they crossed the road before hitting three parked cars and killing Mr Vaughan, from Swansea, and Mr Allen and Mr Parker, from Cwmbran, who were all sitting in a Volvo.
Witnesses saw smoke coming from Potter's lorry and smelt the brakes burning as he drove down the hill. The ABS warning light - indicating problems with the braking system - was also on.
Potter, who had only worked at the company a few days, told the court he would never had driven the lorry had he known the brakes were faulty.
The crash happened after Potter and Gordon's fourth visit of the day to Shorncote Quarry to collect aggregate and deliver it to the park and ride at Newbridge, close to Bath.
Gordon, followed by Potter, drove down Lansdown Lane, a long and steep hill that runs through the village of Weston.
Witnesses saw smoke coming from Potter's lorry and smelt the brakes burning as he drove down the hill.
Describing the brakes failing, Potter told the jury: "I tried the handbrake. I put it on and nothing. I tried putting the lorry into third gear to try and get the engine to slow it down.
"I was really scared because I never had anything like this happen to me before. I blasted the horn. It was the only thing I could think of to warn people that I couldn't stop.
"Somewhere in the back of my head I believed I was going to stop somehow. I am dead. I thought this was the end. I didn't know what was going to happen.
"My hands are on the steering wheel. I locked my arms and pushed myself back into the chair."
Prosecutor Adam Vaitilingam QC told the jury that Gordon was granted an operator's licence in December 2013, the first time he had run such a business.
"The evidence will show that he was not interested in doing it properly," he said.
"His operation was a shambles from start to finish."
Grittenham Haulage was supposed to have a transport manager - responsible for ensuring the lorries were safe - but did not do so in the months leading up to the fatal incident.
Wood was employed by Grittenham Haulage to inspect and help maintain the lorries, carrying out inspections every six weeks.
In police interview, he said the lorries should have been inspected every three weeks, telling officers: "Tipper lorries go through hell."
Virtually no defects were recorded in paperwork for the truck involved in the collision and its brakes were not properly tested, Mr Vaitilingam said.
The truck had 710,000km - almost 450,000 miles - on the clock at the time of the incident.
Grittenham Haulage did not carry out the recommended brake efficiency tests on the vehicle.
"It is further evidence of a poorly run company that just didn't have a grip of what it needed to do to keep its fleet of lorries safe," Mr Vaitilingam told the jury.
The final safety check on the vehicle by Wood was in January last year, weeks before the tragedy.
"If Mr Wood did carry out a safety inspection that day it was wholly inadequate," Mr Vaitilingam said.
"He says that when he looked at the lorry it was in a perfectly safe condition. This sort of catastrophic brake failure doesn't just happen through bad luck.
"This was entirely predictable, the result of poor management and a disregard for the rules and a failure to comply with routine guidelines.
"It was, put simply, an accident waiting to happen."
Mr Potter did not comment as he left court.
Ian Bridge, representing him, had told the court: "On his instructions, he invites me to say to the families how sorry he was that he has been involved in anything to do with their loss."
Remanding Gordon and Wood in custody, the judge said: "It has to be acknowledged that Mr Gordon and Mr Wood have turned up every day for their trial, but the offences they have been convicted of would attract substantial prison terms, so it seems to me that it would be wrong not to start serving those terms now."
Pre-sentence reports will be prepared for both defendants.
Alyson Harris, senior crown prosecutor for the CPS in the South West, said: "This terrible tragedy could have been avoided had the defendants performed their jobs competently.
"The company did not comply with the Traffic Commissioner's conditions. The vehicle was not properly maintained and it was driven on a road it should not have been on and at a time when it was not roadworthy.
"The Crown Prosecution Service has been working with the police team on this difficult and complicated case since July 2015, advising on the law and on the direction of the investigation and with prosecution counsel in preparing the case for trial."
She added: "We hope that these verdicts bring some sense of justice to the victims' families and that all road users take note of the importance of safety and of complying with the rules of the road and of the terrible results that can follow if that is not done."