The reasons for the attack on Leningrad Why Hitler was unable to take the city outright?

The reasons for the attack on Leningrad Why Hitler was unable to take the city outright? When was the city of Leningrad blockaded? during what events? An attempt to break the blockade? Breakthrough itself? Removing the blockade?

The main reasons for the attack on Leningrad: after the capture of the city, the Wehrmacht received the opportunity to reach Moscow from the north; seizure of factories and factories of the city; seizure of the Baltic Fleet base and merchant ships; psychological reason – Leningrad is the cradle of the revolution. The Wehrmacht could not take Leningrad on the move either for a number of reasons: the main striking force of Army Group North was Panzer Group 4, at that time it covered 600 km (30-35 km per day). As a result of such a rapid advance, people got tired, equipment broke down, the rear lagged behind, etc. But the main reason for the stop is the powerful defensive fortifications built by the inhabitants of the city on the outskirts of it. Despite this, on September 8, 1941, after the capture of Shlisselburg and the Mga railway station, the city was finally blocked.
For all 872 days of the blockade, there were many attempts to break through, the main ones were three: 1. Autumn 1941 – battles on the so-called. “Nevsky patch”. 2. Beginning of 1942 – Luban operation. 3.August-September 1943 – Sinyavinskaya operation. The breakthrough date is considered January 18, 1943 – Operation Iskra. The troops of the Leningrad and Volkhov fronts united and liberated Shlisselburg. January 14, 1944 – the troops of the Leningrad, Volkhov, and 2nd Baltic fronts as a result of the Leningrad-Novgorod offensive operation completely lifted the blockade of Leningrad, and on January 20 they liberated Novgorod.