Staying unnoticed in the Secret Annex was threatened in several ways. Besides the chance that unwitting visitors or neighbours of the building might notice something, there was the possibility of burglars, fire in or near the building, light escaping and airborne threats. The people in hiding and the helpers were very alert to risky situations and did a lot to avoid risks.

Outsiders

Especially in the early days, Anne repeatedly expressed her fear of outsiders in the building. In some cases these were strangers, but certainly not always. The sales representatives, pharmacist Arthur Lewinsohn, the accountant and some warehouse men were more or less acquaintances. The plumber, the cleaner, the carpenter and the other warehouse men were strangers to the people in hiding - as far as we know. The acquaintances also posed a threat in Anne's eyes. There was unease when Ans Broks said that she wanted to come to the office for coffee every day at two o'clock.^[1] From time to time, Anne's diary provides clues showing that the people in hiding also took into account the possibility that people living or working in neighbouring premises would discover their presence.

One morning, when Peter van Pels had forgotten to open the bolt on the inside of the street door, Victor Kugler and the warehousemen could not get in. Kugler had to go through the premises of wholesaler Keg on Prinsengracht 265 and only just managed to prevent one of the neighbours from climbing in via a ladder.^[2]

Burglary

Several break-ins and attempted break-ins are referred to in Anne's diaries and narratives. Brother and sister Wijnberg, who lived at Prinsengracht 251 during the period in hiding, said in an interview that they had been in the building as children on 24 March 1943 and had stolen muscatel nuts there.^[3] Anne writes a day later about her first encounter with the phenomenon of burglars.^[4] The break-in of 9 April 1944 is also confirmed by a police report, when the passing night watchman Martonus Slegers noticed the kicked-in door.^[5] The B-version mentions a burglary on the night of 15-16 July 1943. According to the same passage, there had also been an unsuccessful attempt six weeks earlier.^[6] In the A-version, Anne writes about a thief who may have entered with a false key, or at least nothing could be seen on the outside door.^[7]

The wider area, of course, also had to deal with crime. At Keg at Prinsengracht 265, police reports do not reveal any burglaries during the hiding period, but according to the 1963 official report of the National Criminal Investigation Department, there were burglaries. According to the State Investigation Department, by necessity, staff were even regularly present at night.^[8] The daughter of branch manager Jacob Boon knew that her father spent the night in his office more than once during the war years.^[9] In the night of 7-8 April 1943, burglars broke into Elhoek furniture factory at number 261 and stole six hundred guilders and a typewriter.^[10] In November 1941, a coin meter of the Municipal Energy Company (GEB) had also been emptied there.^[11] A few years earlier, the contents of a coin meter in the later Opekta premises had also been stolen by burglars.^[12] Given GEB's policy in the 'small business' market, it was highly plausible that that meter had stayed behind after Opekta's arrival in the late 1940s.^[13] Theft from coin meters was a very common phenomenon. So the presence of such meters certainly posed an additional risk.

Johannes Kleiman and Victor Kugler reported no burglaries or thefts on their premises during the period in hiding, as far as can be verified. Then, in January 1945, Johan Broks - Kugler was still in prison at the time - reported the theft of seventy kilos of sugar from Gies & Co.^[14]

Fire

Building plans for Elhoek's premises at Prinsengracht 261, made in June 1940, show that people there were working with flammable materials and techniques, as they included extensive recommendations on self-closing doors, escape routes and a fire-extinguishing riser.^[15] In the Opekta premises, fire hazards were also taken into account. A few months before going into hiding, there was a small fire when packaging material lying too close to a stove caught fire.^[16] There were 'Minimax' appliances in several places. One was mounted on the landing in front of the bookcase. That location was 'peripheral' from a company point of view, and might have been chosen with the people in hiding in mind: outside the bookcase, allowing periodic maintenance to take place without problems - at least in theory. In the B-version of the diary, Anne writes, with the date 20 October 1942, that they 'got' these devices in the house, which she later changes to 'have'. It is therefore possible that they were fitted in the autumn of 1942, but there is no clarity on this.

Blackout

Due to war conditions, strict blackout measures applied. Users of residential and other buildings were obliged to take measures to prevent light escaping between sunset and sunrise. In winter, curtains had to remain closed for up to 14 hours a day.^[17] Police and Air Protection were quick to take action against violators. In the evening of 4 March 1941, officers kicked in the entrance door of the Opekta premises because a light was on in the hall.^[18] Of course, when the period of hiding began, the people in hiding and helpers had not yet forgotten this. Anne's writings often refer to the closing and opening of the blackout curtains.^[19] During the 1958 restoration, many window frames were replaced. However, some original frames from the Van Pels room are still in the museum collection, and the added constructions for blackout curtains are still attached.^[20]

Air hazard

Anne's frequent comments on shots, sirens and alarms have been compared, where possible, with the air hazard reports preserved in the Amsterdam police archives. A few significant instances of 'air hazard' are shown here.

In the event of an air siren, everyone was obliged to go to the nearest shelter or otherwise take cover. "If the air siren sounds [...] get off the streets!", Nieuws van den Dag, 13 September 1940. On the morning of 6 July 1942, there was no air siren, which would have meant a serious complication for the Franks on their way to Prinsengracht.

Starting on 10 July 1943, Rauter introduced an 'pre-alarm', which indicated that Allied aircraft were entering Dutch airspace without any immediate bomb attacks being expected. The alert was designated an 'air hazard warning'.^[21] A week or two later, Anne mentions the use of this pre-alarm in the B-version when she writes about the air attacks on the Fokker factory in Amsterdam-Noord.^[22] The repeated alarms she lists in her retrospectively written B note that day correspond to the alarms noted by the police in their register.^[23] This makes it plausible that she used her original - and vanished - notes from July 1943 for this B note.

In March 1944, a bomber crashed into a school in Spaarndammerstraat, less than one and a half kilometres from the Secret Annex.^[24] During the air battle Anne witnessed on 3 May 1944, a plane crashed in Van Bossestraat.^[25] This was also a short distance from the Secret Annex. Planes also crashed in Tuindorp Oostzaan and Grote IJpolder that day.^[26] Finally, a plane also crashed into the Carlton Hotel at the end of April.^[25]

Related to the dangers from the air and from anti-aircraft guns was the threat of acts of war and evacuations in the west of the Netherlands. Anne writes at length in early 1944 about the discussions between the people in hiding and the helpers when this danger threatened to take concrete forms.^[27]

The people in hiding were very concerned with their safety. They had all kinds of agreements and arrangements to avoid drawing attention to themselves. Although compliance slackened from time to time, they kept them reasonably well. Neither they nor the people helping them had any control over some dangers: there was obviously nothing they could have done about falling bombs or crashing aircraft. There are no reasons to suspect that laxity or underestimation of security measures contributed to their eventual arrest.