I'm glad that the 'facts' were limited by those quotation marks!

"No two historians ever agree on what happened, and the damn thing is they both think they're telling the truth." Harry S. Truman.

'History, and different perceptions of history, are perhaps the most important factors in the Arab-Israeli conflict.
Accounts of history, interpreting history in different ways, are used to justify claims and to negate claims, to vilify the enemy and to glorify "our own" side.'

So, what do we actually 'know;?

The Palestine refugee problem was created in the course of the 1948 Israeli War of Independence

The war was won by Israel, creating a large number of Arab refugees. Estimates vary from about 520,000 (Israeli sources) to 726,000 (UN sources) to over 800,000 (Arab sources) refugees

This number has grown to include over 4.6 million displaced persons, about 3.7 million of whom are currently registered as refugees with the UNRWA (United Nations Relief and Works Agency for Palestine Refugees). Of these, somewhat over a million live in camps run by the UNRWA

Generally, refugees living in the camps live in conditions of abject poverty and overcrowding.

Israel views the 1948 refugees as hostile persons sympathetic with a belligerent aggressor, and passed a law forbidding their return, and assigning all their land holdings to a custodian of absentee property.

The central practical issue regarding the refugees is the right of return claimed by the Palestinians. UN General Assembly Resolution 194 stated "the refugees wishing to return to their homes and live at peace with their neighbours should be permitted to do so at the earliest practicable date." Resolution 194 further stated that those refugees who do not wish to return are entitled to compensation for properties lost under international law and equity.

The Arab states do not want the refugees. With the exception of Jordan, they are unwilling to give them citizenship. The territory that might be allocated to the Palestinian state, about two thousand, two hundred square miles, is probably too small to house all of them adequately.
Israel and the Palestinian areas both have extremely high population densities - over 300 persons per square kilometer in Israel and over 500 per square kilometer in the occupied territories, including over a million refugees.

These are simple 'facts' the numbers represent thousands of personal 'tragedies.

It would be useful here to discuss ways of resolving the refugee problem not continue to dispute the age old differing perspectives of history as to whether they fled or were forced to flee - there is plenty of 'evidence' and 'facts' to support both view points.