On 1st March 1941, the 12,062-ton British-built merchant tanker S.S. Cadillac went down about 150 miles north of Rockall in the north Atlantic ocean. Torpedoes fired from Erich Topp's U-552 caused an inferno, igniting the highly-flammable cargo. The sinking caused the death of the Master and most of the crew. There were only four survivors, and many of the dead had strong connections to Northern Ireland.
As part of Convoy HX-109, S.S. Cadillac departed Aruba on 23rd January 1941. The destination was Avonmouth, England and the tanker carried 17,000 tons of aviation fuel. On 13th February 1941, the vessel departed Halifax, Nova Scotia on the final leg of its journey to the United Kingdom.
En route, galeforce winds and heavy snow scattered the convoy on 26th and 27th February 1941. S.S. Cadillac and other vessels split from the convoy with disastrous consequences. At 1023hrs on 1st March 1941, the crew of U-552 spotted the straggling Cadillac and another vessel. The submarine evaded Short Sunderland bombers, attempting to move into an attacking position.
A British plane guided H.M.S. Malcolm, H.M.S. Mallow, and four other vessels including Cadillac to form an ad-hoc convoy. S.S. Cadillac lay outermost on the port side. U-552 remained in pursuit.
At 2356hrs on 1st March 1941, U-552 unleashed a pair of torpedoes. They struck the port side of S.S. Cadillac as the mini-convoy sailed around 150 miles north of Rockall in the north Atlantic. The highly-flammable cargo quicky combusted, and fire soon devastated the tanker. Small lifeboats were overwhelmed as the crew attempted to abandon the stricken vessel. Burning fuel and toxic fumes hindered the evacuation, as too did large, cumbersome life rafts.
Cabin Boy Henry Brennan Weir of Newtownbreda, Co. Down died on 1st March 1941 as S.S. Cadillac came under attack from U-552 en route from Nova Scotia.
Master John Frazer Jefferson of Holywood, Co. Down died on 1st March 1941 as the tanker S.S. Cadillac came under attack from U-552 en route from Nova Scotia.
Ordinary Seaman John McDonald of Belfast died on 1st March 1941 as merchant tanker S.S. Cadillac came under attack from U-552 en route from Nova Scotia.
Fireman John Smyth of Norfolk Parade, Belfast died on 1st March 1941 as merchant tanker S.S. Cadillac came under attack from U-552 en route from Nova Scotia.