On the evening of April 24, one of Karachi's most prominent social activists Sabeen Mahmud was shot dead after leaving an event called “Unsilencing Balochistan” that her organization The Second Floor had arranged. Her mother was also injured in the drive-by shooting and is in critical condition.

The event featured two of Pakistan's most vilified human rights activists: Mama Qadeer and Farzana Majeed, who have worked to raise awareness about the southwestern province Balochistan's “missing people.” Qadeer and Majeed are frequent targets of “traitor and terrorist” smear campaigns on social media, and both were recently barred from traveling to a human rights conference in the US.

Sabeen posted this screenshot on Facebook a night before the event:

Sabeen arranged this event, after a previous roundtable on the same topic, also scheduled to include Qadeer and Majeed as panelists, was cancelled at a leading private university called LUMS. Faculty there said they had to cancel the talk because of threats received from Pakistan's top spy agency the ISI.

Also read: Did Pakistani Spies Just Kill a University Debate on Balochistan?

On Twitter , Pakistani activists drew connections between the event and her murder:

When you ask us to put our trust in this state, this is why we fucking can't. — Sadaf Baig (@nuqsh) April 24, 2015

Karachi-based journalist Shaheryar Mirza tweeted:

Tonight before the talk on #Balochistan Sabeen said while smilinf, “thankfullt we have not been told by anyone to not hold this talk”. — Shaheryar Mirza (@mirza9) April 24, 2015

Traumatising beyond belief. We were always scared for her, but didn't think we'd actually see this say. https://t.co/JxJCnbKAJ4 — Raheel Khursheed (@Raheelk) April 24, 2015

Balochistan, Pakistan's largest, least populated and poorest province is witnessing its fifth separatist movement since 1947. Public discussions on Balochistan's war are rare and reporting from there in thin.

According to the Human Rights Commission of Pakistan, since 2010, the bodies of hundreds of Balochistan’s “missing people” have turned up dead bearing torture marks. In 2013 alone, 116 bodies were found across the province, 87 of which were identified by families who accused Pakistan’s security agencies of abducting their loved ones.

Watch: GV Face: Breaking Pakistan's Silence on Balochistan

Opposition politician and human rights activist Alizeh Haider tweeted:

You speak you die. ISI ‘s message, loud and clear to all those speaking up for Balochistan. #UnsilencingBalochistan #SabeenMahmud. — Alizeh Iqbal Haider (@AlizehIHaider) April 24, 2015

A follower responded to her by saying she could have been silenced by the Balochistan Liberation Army, an armed faction fighting for the province's independence from Pakistan. The BLA is banned in Pakistan.

@Adil_A93 @omar_quraishi clamp down on LUMS initial seminar was also BLA? — Alizeh Iqbal Haider (@AlizehIHaider) April 24, 2015

Our wonderful, friend heroine and fallen soldier @sabeen May you rest in peace but we will not until your killers are found and prosecuted — Fifi Haroon (@fifiharoon) April 24, 2015

Karachi's shining social activist

Sabeen's The Second Floor, commonly known as T2F, was a community space for open dialogue that wanted to bring about social change in Pakistan's largest city Karachi.

According to their website, since it was founded in 2007: “T2F has hosted hundreds of events, ranging from poetry readings and film screenings, to vibrant debates on critical issues. With the support and participation of musicians, artists, writers, film makers, scientists, comedians, thought leaders, and engaged audiences, T2F has contributed to revitalizing Karachi’s cultural landscape and has provided an alternative, independent, safe space for discourse.”

RIP. Activist @sabeen behind Pakistan's first hackathon reportedly shot in Karachi today. Profile from @LoisParshley http://t.co/Eb8u8wC2Wj — WIRED (@WIRED) April 24, 2015

Sabeen was like titanium. So strong. So dignified. In every way. A huge supporter of all voiceless people. A voice. Ya Allah. — Mosharraf Zaidi (@mosharrafzaidi) April 24, 2015

Wajahat Ali, a Pakistani-American journalist and activist posted on Facebook: