The following is an excerpt from
Rabbi Hayim Halevy Donins classic
To Be a Jew (Buy the book from Amazon, Click here for info)
"The saddest and most tragic day in the year is the fast of the ninth of Av.
It is a day of fasting and mourning which commemorates the destruction of the First
Temple..." [and the Second temple and the expulsion of 1492 in particular]
"
Though the Jewish State was reestablished in 1948, and Jerusalem was
reunited in 1967 under Jewish sovereignty for the first time since 70 C.E., the
significance of Tisha b'Av has nevertheless been reaffirmed by contemporary thinkers and
scholars.
In the first place, the Temple itself - the destruction of which is the basic reason
for the mourning of Tisha b'Av - is still not restored. The Temple Mount in fact was
appropriated by Islamic leaders, who in the year 691 C.E. built on Judaism's holiest site
a major Islamic shrine. This only highlights the Temple's loss to the faith of Israel.
Secondly, there is no more appropriate occasion in the year to remember, mourn and
grieve over all those occasions in Israelīs history which were steeped in sorrow and
suffering, in death and torture, in cruelty and oppression, all of which reached their
climax in the European holocaust (1940-1945) when over a third of all the Jewish people,
more than six million men, women, and children, were systematically and barbarically put
to death after the most unbelievable suffering.
Tish b'Av is a day of total fasting. As on Yom Kippur, eating or drinking anything from
before sundown on the eighth of Av till nightfall on the following day is forbidden.
In the synagogue following the evening services, the Book of Lamentations
(Megillat Aichah), is read in the mournful chant traditionally associated
with it. "