Review of the 1755 Lisbon Earthquake Based on Recent Analyses of Historical Observations - Historical Seismology: Interdisciplinary Studies of Past and Recent Earthquakes - page 278

No damage
Slight cracking
Important cracking
Partial collapse
Total collapse

Damage Statistics - Lisbon 1755

70%

60%

50%

40%

30%

20%

10%

0%

Churches Convents Palacies Hospitals Small

Churches

Other
structures

Fig. 15 Damage statistics in monuments

In relation to the housing stock, the situation is much more difficult to analyse,
due to the different estimates presented by various authors. According to Pereira
de Sousa (1929), confirmed in “Mem orias Paroquiais”, the population of Lisbon at
the time was around 150,000 inhabitants with age above 7 years. The Census in
1758 indicates 34,000 apartments and 20,000 houses. Only 10-20% were in safety
conditions of habitability, 60% exhibit important damage and were inhabitable, and
10-20% collapsed.

Fig. 16 Structure with slender walls without falling (Opera House or Real Theater) denoting dam-
age caused essentially by the fire