Plymouth is marking 80 years since air raids devastated the city during the Blitz in 1941.
The Blitz was a heavy period of bombing on the UK by Nazi Germany's Luftwaffe during World War Two, which started in mid-1940 and continued until the following May.
The first bombs fell on Plymouth on 6 July 1940, with the city's naval base and docks making it a major target.
However, the heaviest instances of bombing on the area took place on 20 and 21 March, and then 21, 22, 23, 28 and 29 April 1941, with 900 people killed and 40,000 made homeless over seven nights.
Various events are being held in Plymouth on Saturday, to commemorate the first night of the heavy attacks.
Dr Harry Bennett, Associate Professor Plymouth University, said those working at the naval base at the time would have seen "a sea of fire".
"A city, the heart of which was burning," he said.
"People for miles around could see the reflections upon the cloud and they wondered what's happening to Plymouth.
"Well, people at the naval base could see the terrible destruction that was being wrought out there in the city.
"Raids that would leave hundreds dead."
London aside, Plymouth was one of the most heavily bombed cities in the country.
More than 200,000 incendiary bombs were dropped on the city, along with more than 6,600 high explosive bombs.
Dr Bennett said the 80th anniversary of such events, also including Dunkirk and the Battle of Britain, will be one of the last with a "significant number of people" who can remember them.
"This is a period that is literally passing from human history into book history, and that makes me quite sad in a number of ways because you think about the people that we're losing and we're losing those memories," he said.
"The people who could remember looking out upon a burning city in 1941 and what it actually meant to them.
"The people who in the post-war period lived in the bomb sites, quite literally played in the bomb sites, and who helped to rebuild a city like Plymouth into the glory that it is today," he added.
According to Plymouth City Council figures, 3,754 homes were destroyed and 1,174 civilians were killed between the first bombs on 6 July 1940 and 30 April 1944.
However, Dr Bennett said Plymouth must be regarded as a "modern miracle of post-war design".
"We have to regard it as such because it actually works," he said.
"But in terms of what you see [now], you're looking at the ghostly reminders of a few buildings left over from that period which speak of a city which effectively disappeared in 1941."