Beaminster tunnel landslide warning ahead of deaths
A couple were killed when their car was engulfed by a wall of mud during a landslide "waiting to happen", an inquest heard.
Rosemary Snell, 67, and Michael Rolfe, 72, from Somerset, were buried for 10 days before their bodies were found in Beaminster Tunnel, Dorset, in 2012.
Land agent David Ashcroft said he raised concerns in 2004 about tree felling undermining land stability.
Dorset County Council said the trees had been in a "poor condition".
The county's coroner recorded verdicts of accidental death at an inquest in Dorchester.
Mr Ashcroft told the inquest that his warnings about the felling of 42 trees had "fallen on deaf ears".
He added: "It is a well-known geographical fact, if you cut down trees or vegetation on a slope of more than 45 degrees, you are going to get some kind of landslip movement."
Responding to Mr Ashcroft's concerns, Mike Winter, head of Dorset highways management said: "It's rather more complex than A-level geography."
He said a small landslip in 2009 was deemed only to be surface soil movement with no danger of a full landslide happening.
The inquest heard the fatal landslip happened during the wettest summer in 100 years. Between 100mm and 125mm of rain had fallen in the Beaminster area in the 24 hours before the couple died.
Patricia Roberts, from Chard, described how she and her husband had been travelling behind the couple's silver Skoda on 7 July 2012 and saw its lights "disappear" at the far end of the tunnel.
She said they assumed the vehicle had gone through but decided not go attempt to follow for fear of a tunnel collapse.
The hearing heard how firefighters were later called and used thermal imaging equipment to try to establish if anyone had been trapped in the landslide, but nothing showed up.
Mr Rolfe's son Mark asked Mark Greenham, station commander at Beaminster Fire Station, if any other technology existed which would have identified people trapped under the landslide.
He said there was no alternative equipment.
Mr Greenham said: "I made the decision to cease the search as there was no information that anyone was trapped.
"I also didn't want to put anyone in my crew in danger."
Ms Snell and Mr Rolfe were reported missing and their bodies were found nine days later.
Mark Rolfe described his father as a talented doctor who worked in Africa specialising in the study of Aids.
Ms Snell's friend Carol Walker said that she had described Mr Rolfe as her "soul mate".
Post-mortem examinations concluded Mr Rolfe died of a fracture of the cervical spine due to being trapped and Ms Snell suffered chest compression.
Recording verdicts of accidental death, coroner Sheriff Payne said: "Their deaths would have effectively been instantaneous.
"What happened was not foreseeable and wasn't of a criminally negligent nature."
The road was closed for more than a year after the landslide to allow a £2.1m repair and stabilisation programme to be carried out.