Six people have died and a seventh is critically injured after a multi-vehicle crash in Birmingham in the early hours of Sunday morning.
Police have appealed for witnesses to the "harrowing" collision as they try to establish how it occurred.
Three men were killed when they were thrown out of their car while a black cab driver and his two passengers, a man and woman, died after the vehicle was left on its side.
A fourth man travelling in the car remains in a critical condition at the city's Queen Elizabeth Hospital.
The taxi driver has been named as "happy, loving" father-of-six Imtiaz Mohammed.
He had six children all aged under 15 and was described by his father as a "happy, loving and friendly guy".
Surrounded by the 33-year-old's other relatives at the family home, Ikhtiar Mohammed recalled how his "heart sank" as police knocked on his door at 5am on Sunday.
The 65-year-old said: "I knew there was something wrong, as soon as I saw them.
"I thought to myself, 'which of my sons is hurt', I just knew something was seriously wrong."
He said that Mr Mohammed's wife, Nargas Gul, was still in deep shock while relatives struggled with how to break the news to the couple's five daughters and son.
One of their girls had been due to celebrate her fourth birthday on Monday.
His younger brother Noorshad Mohammed revealed how just moments before the fatal crash, his sibling rang his wife to tell her he would be coming home.
The 32-year-old said: "It was his last job of the night.
"That was the last time she spoke to him.
"He was going to come home - he rang his wife at 1am, and they were going to have something to eat.
"And then that was it. That was the last time they spoke."
Older sister Nassrin Bibi paid tribute to her brother and said the family had been "shattered" by what had happened.
Mr Mohammed worked for local firm Castle Cars, who said in a statement: "Imtiaz was a wonderful young hard-working family man", who was "loved and respected by all".
The crash occurred shortly after 1am at the entrance to the underpass on Lee Bank Middleway, near Edgbaston, at the junction of Bristol Road.
Six vehicles were involved in the incident, West Midlands Ambulance Service said.
Five ambulances and three paramedics were sent to the scene.
West Midlands Fire Service said 40 firefighters helped in the aftermath of the "horrific" crash, and were met with what they described as a "complex scene, spread over some distance".
West Midlands Police described the circumstances of the incident as "very difficult and upsetting".
Relatives of the victims arrived at the scene on Sunday morning, desperate to find out what happened.
One passer-by, who asked not to be named, said: "It is really horrific.
"A man turned up here and said the police had knocked on his door this morning and told him one of his relatives had died in the crash.
"He didn't know what had happened to the second person in the car so he was at the scene trying to find out. It must have been horrendous for him.
"People have told me there were bodies scattered across the carriageway."
All first responders at the scene are doing their very best in very difficult and upsetting circumstances. This is a very serious incident. If you saw the crash happen or the circumstances leading up to it, please call us now on 101.— West Midlands Police (@WMPolice) December 17, 2017
A West Midlands Ambulance Service spokesman said a man and woman in the first car managed to escape with "relatively minor injuries", and were taken to Heartlands Hospital.
He added: "The second vehicle, a 'black cab', was on its side.
"Sadly, there was nothing that could be done to save the driver and he was confirmed dead at the scene. The man and woman in the back were rapidly extricated.
"Unfortunately, it was not possible to save the woman and she was also confirmed dead at the scene.
"The man was taken on blue lights to the major trauma centre at the Queen Elizabeth Hospital Birmingham with the MERIT trauma doctor travelling with the crew. Sadly, he died at hospital."
There were four men in the third car, the spokesman said, three of whom were confirmed dead at the scene.
The fourth was taken to the major trauma centre at the Queen Elizabeth Hospital Birmingham in a critical condition.
Of those travelling in the three other cars involved in the crash, a man and a woman were treated for minor injuries, one man was discharged after assessment and another said he did not require any assistance.
The Hazardous Area Response Team of West Midlands Ambulance Service described it as a "significant incident".
The road will remain closed on Sunday.