J. Otto Pohl wrote  about the history of the deportations, and here is an excerpt from his post:
On 18 May 1944, the Soviet NKVD began the systematic round up and deportation of nearly the entire Crimean Tatar population from their ancestral homeland to Uzbekistan and the Urals. Early in the morning armed troops of the NKVD started knocking on the doors of Crimean Tatar houses and informing the inhabitants that they were to be deported. The official explanation given for this mass uprooting of women, children, elderly, Red Army veterans and even members of the Communist Party was the false claim that the Crimean Tatar nationality had collectively betrayed the Soviet Union and collaborated with the Nazi occupiers. […]
On the first day of the operation, the Soviet security organs took 90,000 people to train stations of which 48,400 began their journey eastward (Bugai, doc. 11, p. 138). The following day the number of Crimean Tatars transported to rail stations increased to 165,515 of which 136,412 had been loaded onto train echelons bound for Uzbekistan (Bugai, doc. 12, p. 138). Finally on 20 May 1944, the NKVD completed the operation. They reported loading a total of 180,014 Crimean Tatars into 67 train echelons of which 63 with 173,287 deportees were already on their way to their new destinations (Bugai, doc. 13, pp. 138-139). On the same day the NKVD also reported mobilizing 11,000 Crimean Tatar men for forced labor, bringing the total number of Crimean Tatars removed from Crimea to 191,014 (Ibid.). A total of 23,000 soldiers and officers of the internal troops of the NKVD and 9,000 operative workers of the NKVD-NKGB participated in this operation (Bugai, doc. 21, p. 144). The NKVD succeeded in ethnically cleansing Crimea of its indigenous population in a mere three days.
Maria Sonevytsky of My Simferopol Home posted photos from the memorial event  that took place in Simferopol  on May 18 – and described the current plight and the attitudes of the Crimean Tatar who have returned to live in Ukraine:
Over dinner in Simferopol with my adopted Crimean Tatar family last week, Ayder, a veteran of the Crimean Tatar human rights war against the USSR, used the term “genocide” to describe the present Ukrainian non-policy towards Crimean Tatars. He cited the attacks by militia groups on Crimean Tatar businesses and homes over the last twenty years, the inadequate implementation of protections for the indigenous people and the minority population, the alarmist attitude towards their Muslim minority group, framed without cause for extremism and denied land permits to build a new sobornaya mechet’, and so on. In my cautious academic way, I suggested that genocide was perhaps too strong a term: as careless and irresponsible as the Ukrainian government has been towards the Crimean Tatars, an indigenous people of Crimea, genocide implies a systematic, violent destruction of an entire ethnic group. It is more sinister than the bumbling indifference of the Ukrainian state. No, he asserted: “we are uncomprehending witnesses to a subtler form of genocide. The Crimean Tatars are being choked out of existence.” […]
Here is what Maria writes about the changes that must occur for the situation to improve:
[…] A multi-ethnic Ukraine must exist, and its ideal should not be for stalemate, a platitudinous tolerance; Ukraine must seek a deep acceptance and respect for its diverse minority and indigenous groups. A propos to the Crimean Tatar situation, the Ukrainian government should finally approve a law to grant the indigenous people of the Crimean peninsula rights and protections as a threatened, indigenous people of their ancestral homeland: land rights, education in the native language, an end to religious discrimination, and ultimately, a right to self-determination within the territory of Ukraine.
We can learn from a [Hutsul ] musician who I spoke to a few weeks ago, during the Easter holidays. We sat in his ancient Volga as he played me old cassette tapes and told me his deportation story. His family had been deported to Siberia during the war and not allowed to resettle in the [Ivano-Frankivsk ] oblast until the 1970s. Reading about the Crimean Tatar non-violent resistance of the 20th century, their fierce support of the Orange revolution in 2004, and their annual celebration of Taras Shevchenko's birthday, he asked me for a recording of a Crimean Tatar violinist from whom he could learn some traditional melodies. I asked him why, and he said, “to show my respect, as they’ve been showing it to us.” In place of fear, respect. In place of dim hostility, a desire to understand. In place of ignorance, education. […]