In 1942, as losses among Canadian air crew mounted and the failed raid on Dieppe left hundreds of Toronto families with a loved one killed or in a German prison camp, officials started a formal effort to keep track of the city’s dead.

As the war ground on, a file of typed index cards at the city clerk’s office at what is now Old City Hall grew and grew, until there were thousands. Casualty lists were scoured for Toronto addresses as they appeared. After the war, the cards became the research tool for preparing the Book of Remembrance, which is now at Toronto City Hall.

Citizens answered newspaper ads asking for names that might have been missed, and the file grew larger. Eventually, the cards documented more than 3,300 people who were killed in the war and had next of kin in Toronto. They died over Germany on air raids, fighting in Normandy and Italy, or as their warships or merchant vessels were torpedoed. Many were killed in training accidents. One is buried in South Africa and one in Yukon.

In the modern city archives, the cards fill 12 boxes.

I was given access to the card file earlier this year after making an access-to-information request, and paid many visits to the city archives, entering the basic details on each card into a laptop. It turned out that I was committed to what ended up being 55 hours of data entry, working steadily through box after box. Letters and scraps of personal information were a helpful reminder that I was dealing with records of real people, and that the grief over their deaths had once been fresh, and in some cases life-destroying.

I then geocoded each address where possible and transferred the records to KML for display in an interactive map.

A map overlay joins two kinds of knowledge: our existing picture of the familiar city and some new knowledge superimposed on it. Overlays can take many forms but one of the most powerful, and sometimes disorienting, kinds has to do with history. (The author Simon Schama wrote that the attraction of history for him was in the intersection of the familiar and the unfamiliar.)

OpenFile’s map shows, where possible, the homes listed as the next-of-kin address of 3,224 Toronto residents killed in the war. The poppies designate addresses, rather than individual people, so where it is necessary to put two or more people in a household, multiple people share the poppy. Four addresses show three people each and 95 show two. This doesn't necessarily reflect a family relationship, though often it does.

The map is an exercise in recovered local memory. For example, it must have been well known in the neighbourhood west of Queen St. and Spadina Ave. that five local men had died at Dieppe but that experience is hard to reconstruct now except through this kind of project. One was from Cameron St., one from Vanauley St. and three from Augusta St., numbers 20, 26 and 44.

From the spreadsheet, we ordered the full service files of four people, which led to the stories that OpenFile's Jane Armstrong will share this week:

• Private Frank Egerton, killed in Italy, and his brother Sergeant George Egerton, killed at Caen in Normandy. They lived at 8 Foxley St., near Ossington Ave. south of Dundas St. W. A third brother, also in the infantry, survived the war.
• Army Lance-Corporal Kenneth Jackson, whose widow lived at 356 Jones Ave., north of Gerrard St. E. Jackson was captured at Hong Kong and survived years in a Japanese prison camp only to die, weakened by malnutrition, on the American ship taking him home.
• Naval telegraphist Gregory Clancy, from 72 Woodside Ave., near Runnymede Rd. and Annette St., killed as HMCS Esquimalt was torpedoed off Halifax toward the end of the war.

Each data point on the map includes a rough start on searching for the serviceman at the Commonwealth War Graves Commission database. I have filled in the surname, nationality and branch of service in each case, which narrows down the search. It works less well for more common surnames. (The Veterans Affairs database is in some ways better, but the way the URLs are structured made it easier to link to the war graves commission site.)

The addresses on the map are the earliest known next-of-kin addresses on the cards. Typically they seem to have been prepared from casualty lists issued at the time, screened for Toronto addresses.

Cards that showed addresses outside the GTA, obvious workplaces or rural route or general delivery addresses (like “RR1, Todmorden, Ont.”) were not included on the map. I realized late in the process that it was a mistake not to have counted these, but it was in the range of about 100.

On the other hand, addresses on streets that no longer exist were geocoded where possible, and provide a quick tour of how dramatically parts of Toronto were redeveloped after the war. Some of these points look odd to the modern reader, but they are placed as correctly as I can manage, using fire insurance atlases and city directories:

• Two people had next of kin who were residents of Centre Island.
• Three lived on Applegrove Ave., which once ran west off Coxwell Ave. north of Queen St. E. but was obliterated after the war in favour of a north-south street structure.
• Three lived on Empress Cres., part of the lakeshore Parkdale neighbourhood that was bulldozed to build the Gardiner Expressway. As a result, these points are placed more or less on the Gardiner near Jameson Ave. As best I can determine, this is where they belong.
• Many more lived in the areas redeveloped to build Alexandra Park, Regent Park and Moss Park on streets, or parts of streets, that no longer exist.
• One lived on Division St. which ran between Spadina and Huron St. south of Willcocks St. He is placed more or less on top of a building that’s part of the Centre for Addiction and Mental Health.
• Three lived on Royce Ave., which became part of Dupont St. after the war.

Geocoding is a fallible process, and I can’t promise that each point falls in exactly the right place.

The cards are more reliable for personal and domestic information than military information; I found this aspect of it frustrating. Especially for army casualties, regiments are listed inconsistently. Without the time available to cross-reference more than 1,000 soldiers with the Commonwealth War Graves Commission database, I can only present the data as it exists in the cards. Also, while dates were mostly entered in a day/month/year format (31/6/1944), they sometimes turned out to be in a month/year/day format, which if the day falls in the first 12 of the month, is nearly impossible to spot.

If you live in the older part of Toronto, you might want to think about what follows. Last year, in the introduction to a Riverdale First World War casualty map I created for the Toronto Star, I wrote:

The older a house is, the more of the texture of everyday life has flowed through it — birth, death, joy, tragedy. Some people who live in old houses enjoy the traces of people who lived there before, like coal grates and worn floorboards, and others carefully erase them all.

It’s rooted in personal things: our attitude to home, history and culture play a part.

A home pinpointed on the map may be where you now live. Whether you want to know this is for you to decide.