The first reports of the accident were published in The Times on Christmas Day, with the headline "Frightful Accident on the Great Western Railway".
Reporting was hindered by "strict reserve on the part of all the company's servants", but the account given in the newspaper could, according to The Times "be relied on as substantially correct".

The train left Paddington at about 4:30 am with about 38 passengers aboard "chiefly of the poorer class".
Just before 7:00 am, in Sonning cutting, the train ran into soil that had slipped from the side of the cutting onto the track, covering it two or three feet deep.
The engine and tender were derailed immediately and "the next truck, which contained the passengers, was thrown athwart the line, and in an instant was overwhelmed by the trucks behind, which were thrown into the air by the violence of the collision, and fell with fearful force upon it".
Eight passengers were killed and sixteen others were "more or less severely wounded".
After being extracted from the wreckage, the injured were taken to the Royal Berkshire Hospital at Reading, and the dead were carried to a hut near the site of the crash.
 Among the wounded were Thomas Martin Wheeler, a radical activist, and his wife.

An inquest on those killed was opened at 3:00 pm on the same day, in a nearby public house, but The Times's correspondent could not obtain details of the evidence produced there.
However, he wrote that, in the opinion of people living in the neighbourhood of the crash, the part of the cutting where the accident occurred was not secure; the cutting was deep, the sides were too steep and the soil through which it was cut was said to be of a "loose springy nature" that showed a tendency to slip.
Bank-slips had occurred before in the cutting near to the crash site and these had been reported to the Great Western Railway.
However, the GWR watchman responsible for this section of the line had reported that when examined at 5:00 pm on the day before the accident "there was not the slightest appearance of there being any danger of a slip taking place".
Later it was determined that the slip must have occurred after 4:30 am, because this was the time that the "up" mail train passed through the cutting on its way to London.

Isambard Kingdom Brunel, engineer of the GWR, on hearing of the crash left London with about one hundred workmen, in a special train, to clear the soils from the line.
The first reports of the accident were published in The Times on Christmas Day, with the headline "Frightful Accident on the Great Western Railway". Reporting was hindered by "strict reserve on the part of all the company's servants", but the account given in the newspaper could, according to The Times "be relied on as substantially correct".
The train left Paddington at about 4:30 am with about 38 passengers aboard "chiefly of the poorer class". Just before 7:00 am, in Sonning cutting, the train ran into soil that had slipped from the side of the cutting onto the track, covering it two or three feet deep. The engine and tender were derailed immediately and "the next truck, which contained the passengers, was thrown athwart the line, and in an instant was overwhelmed by the trucks behind, which were thrown into the air by the violence of the collision, and fell with fearful force upon it". Eight passengers were killed and sixteen others were "more or less severely wounded". After being extracted from the wreckage, the injured were taken to the Royal Berkshire Hospital at Reading, and the dead were carried to a hut near the site of the crash.  Among the wounded were Thomas Martin Wheeler, a radical activist, and his wife.
An inquest on those killed was opened at 3:00 pm on the same day, in a nearby public house, but The Times's correspondent could not obtain details of the evidence produced there. However, he wrote that, in the opinion of people living in the neighbourhood of the crash, the part of the cutting where the accident occurred was not secure; the cutting was deep, the sides were too steep and the soil through which it was cut was said to be of a "loose springy nature" that showed a tendency to slip. Bank-slips had occurred before in the cutting near to the crash site and these had been reported to the Great Western Railway. However, the GWR watchman responsible for this section of the line had reported that when examined at 5:00 pm on the day before the accident "there was not the slightest appearance of there being any danger of a slip taking place". Later it was determined that the slip must have occurred after 4:30 am, because this was the time that the "up" mail train passed through the cutting on its way to London.
Isambard Kingdom Brunel, engineer of the GWR, on hearing of the crash left London with about one hundred workmen, in a special train, to clear the soils from the line.
Sonning Cutting railway accident