Here's a short story:

(CNN) -- Fang Lizhi, a famed Chinese democracy activist, has died in the United States, where he fled in exile more than 20 years ago, fellow activists said. 

He was 76. 

Fang died Friday in Tucson, Arizona, according to Wang Dan, a prominent student leader of the 1989 Tiananmen Square student protests. 

"My most, most respected teacher Fang Lizhi has died," Wang wrote on Facebook. "I am immensely sad. I hope that the Chinese people will forever remember him, that in our history there was a thinker named Fang (Lizhi) who inspired a 1989 generation and awakened the people to aspire to human rights and democracy." 

He added, "Sooner or later, there will be a day when China will be proud of Fang Lizhi." 

Fang, an accomplished astrophysicist, served as vice president of the elite University of Science and Technology at Hefei, Anhui province. He was dismissed from his job and expelled from the Communist Party in 1987, blamed for sympathizing with student protesters. 

He was one of the three noted intellectuals who were publicly criticized during the "anti-bourgeois liberalization" campaign at that time, though Fang continued to speak out for democracy. 

In early 1989, he wrote an open letter to Communist Party leader Deng Xiaoping, calling for the release of Chinese political prisoners. 

After the bloody crackdown during the Tiananmen protests on June 4, 1989, Fang and his wife Li Shuxian sought refuge inside the U.S. embassy in Beijing. 

A year later, they were allowed to leave China for Britain and were soon after granted political refuge in the United States.  (End of story)

Provide your best guess for the following question. Give ONLY the guess, no other words or explanation.

For example:

Guess: <most likely guess, as short as possible; not a complete sentence, just the guess!>

Here are a few examples of questions and answers:

Question: What kind of scientist was Fang?
Guess: astrophysicist

Question: Where did he work?
Guess: University of Science and Technolog

Question: Where was that located?
Guess: t Hefei, Anhui province

Question: what was his title?
Guess: vice president

Question: Does he still have that job?
Guess: No

Now answer the following question in the same format.

Question: Why did he leave?

Due to the Tiananmen protests