Place	Welwyn Tunnel
Date	Sunday 10th June 1866
Railway Company	Great Northern Railway
No. of Fatalities	2
Cause of Accident	Collision
Description	Engine failure caused the first freight train to come to a stand in the tunnel. The guard failed to protect the rear of the train and the failed train was hit in the rear by a Midland Railway freight train. This in turn was hit by another freight from the Great Northern. One of the trains held barrels of oil and this ignited filling the tunnel with smoke and fumes.

List of Fatalities

0 of the 2 fatalities that have been identifed so far are listed in the table below together with brief notes on any other information found so far.

The last column shows the General Register Office (England and Wales), Statutory Register (Scotland), General Register Northern Ireland or Civil Registration for Ireland reference where this has been identified.

Surname	First Names	Age	Occupation	Residence	Notes	GRO/SR/GRONI/GROIE Reference