A motorist has described how he looked over to see his wife "covered in blood" after a bucket-sized piece of concrete was dropped on to their vehicle from a bridge.
Steve and Carol Manley were driving home after visiting some friends when the missile was launched from a bridge on the A12 in Essex, leaving Mrs Manley with fractures to her face and ribs, and internal injuries.
"There was a bump on the roof of the car, as far as I could tell," her husband said.
"I thought I had hit something in the road. When I turned around and looked at my wife to ask her what it was, I noticed that the front of the car was destroyed.
"My wife was covered in blood. There was a concrete block on her chest and leg."
Mr Manley said his 57-year-old wife had only recently left hospital following an operation on her stomach, where the concrete block landed.
"My first reaction was to try and get the concrete block off of my wife," he told a press conference.
"The concerns that were running through my mind were that my wife couldn't breathe, she couldn't see, there was blood pouring from her face.
"I was concerned because she had an operation on a spinal injury about two or three years ago.
"Only recently (she had) come out of hospital from having an operation on her stomach and the concrete block was on the stomach so you can understand I was in no state to know anything or do anything."
Mr Manley said he had been driving at about 45mph and enjoying a "quiet conversation" with his wife when the block hit their vehicle at 10.05pm last Thursday.
He escaped with minor cuts and bruises.
His wife is now recovering from her ordeal at Broomfield Hospital, in Chelmsford, Essex.
Pictures released earlier today show her with a bloodied face, oxygen mask and severe bruising around her eyes.
The pair were hit just 40 minutes after mother-of-two Lisa Horne, 26, escaped unharmed when a rock the size of a football smashed on to her windscreen.
The 26-year-old was driving under another bridge with her 48-year-old mother Stella on the same road when their Vauxhall Astra was struck.
Mr Manley said his wife would get better physically, but would continue to carry mental "scars" in the future.
He said: "Carol is frightened now to sit in the front seat of a car, she doesn't want to be in the car.
"Now unfortunately Carol has to be in the car because she's disabled, she's got rheumatoid arthritis and she's epileptic, so she cannot go on long journeys on her own.
"Physically she's going to get better, mentally we're going to worry about the scars in the future when they come up. All I can say on that one is, God-willing she won't suffer any scars."
Mr Manley warned that the two attacks - which are both being treated as attempted murder - could spark a "craze of stupidity".
"This could happen again because of some thoughtless people or person that thinks it's fun to throw pieces of concrete at innocent people and try to kill them so they can watch blue lights come flying down the road," he said.
"Maybe they get their satisfaction out of this but they should think of the people that are suffering the shock, the injury - how would they feel if there was a six-month old baby in the car when that concrete block hit?
"I don't think they would be impressed but with their warped sense of humour they may enjoy this.
"Please, please everybody out there if they hear of anyone out there jokingly saying, 'I know what happened, I was there, it was me,' please go to the police.
"There are hundreds of miles of road this country's got bridges across and this could start a craze of stupidity, of injuring and trying to kill people."
The incident took place as the car passed under West Hanningfield Bridge near Galleywood.
Recalling the aftermath of the attack, 56-year-old Mr Manley said he pulled over before calling emergency services, adding that medics "saved my wife's life".
Friends came down and "helped us immensely", he said.
Flanking Mr Manley at the press conference were his daughters Sarah Smith, 30, and Michelle Clifton, 37, who wept as she recalled telling her children their grandmother was in hospital and she could not guarantee she would be all right.
She said: "My mum has 11 grandchildren. I don't want another person to get the phone call that I got last Thursday evening telling me I could be facing the possibility of losing both my mum and my dad, telling my children that their nan is in hospital and I can't guarantee that she's going to be all right.
"Nobody should have to take that phone call, ever."
The couple have another daughter, Kelly, 36, and a son called Lee, 33, who were not present at the statement today.
Police are now investigating whether the attack at West Hanningfield Bridge and the one which took place 40 minutes before have any definite links to more than 30 similar incidents on bridges along the A12 during the past three years.
In the earlier incident, Ms Horne was driving to Chelmsford after a day's Christmas shopping at Lakeside shopping centre when the large piece of granite slammed on to their bonnet under the Fryerning Lane Bridge, near Ingatestone.
She later recalled seeing "a shadow coming down from the sky" before there was "the biggest explosion" as the rock hit the car.
And she said she believed someone had been "looking over" her at the time, adding: "Obviously, if I was going any faster, it may have been a different story. I do feel very lucky."