Parveen Rehman, a leading social worker in Pakistan was shot dead by unidentified gunmen  amid rising ethnic, sectarian and criminal violence in Karachi city. 56-year-old Parveen was killed right outside Orangi, on March 13, 2013, where she headed the Orangi Pilot Project  (OPP), one of Pakistan's most successful non-profit organisations, which helps poor communities.
Orangi is considered Asia's largest slum  and houses close to a million people in Karachi. A trained architect, Parveen also worked tirelessly to document land in the ever growing slum and in Karachi, to protect it from the city's notorious land mafia,  who she had been receiving death threats from for years. 
On his blog Alexressed  Diary of a concerned Pakistani, Ale Natiq writes:
Most people know her as the Director of the Orangi Pilot Project but she was more than a mere NGO Director. She and her organisation have left footprints across a wide area of Karachi and have influenced several thousand lives. It will not be unfair to say that she influenced the lives of half a million people or half the population of Orangi in one way or the other. Karachi’s slums and katchi abadis have lost a mother figure.
Among other milestones, the OPP is known for initiating one of the most successful community-driven sanitation programs in the world. Since its inception in 1980, it has helped 2 million people  improve their sanitation by installing underground sewer pipes and indoor toilets across Pakistan. 
@NPRInskeep : Outsiders would get a little tense just visiting Orangi, the vast gang-infested zone of Karachi where Rahman cheerfully worked each day.
The day Parveen was murdered, seven other people were killed in various incidents of violence  in the city. There was a feeling of extreme loss and grief among Pakistan's Twitterati. Pakistan Director at Human Rights Watch Ali Dayan Hasan  tweeted on March 14, 2013:
Others including journalists Beena Sarwar, Mohammad Hanif and columnist Cyril Almeida echoed his sentiments:
@cyalm (cyril almeida) : A selfish thought tonight: am sick at the thought of the growing number of ppl in my phone book who have been cut down. Too much death.
@BhopalHouse (Faiza S Khan) : I realise, I've known for some time, that no depths to which Pak won't sink. Grateful that I still feel heartbroken. Soon that too will end.
Parveen's Fight against Karachi's Land Mafia
Before joining the OPP in 1982, Parveen worked as a architect. She continued to teach at various architecture schools over the years to create socially-responsible architects in the country. Parveen, had spent years documenting land in the fringes of the ever-expanding metropolis Karachi. According to her students  and colleagues she had been receiving death threats from the mafia involved in grabbing precious land in the city: 
Ms Rehman was an ardent compiler of the record of precious lands, which were on the fringes of the city in shape of villages but were speedily vanishing into its vastness because of ever-increasing demand by thousands of families who were shifting to Karachi every year from across the country. She said on record that around 1,500 goths (villages) had been merged into the city since 15 years. Land-grabbers subdivided them into plots and earned billions by their sale.
SesapZai  an artist from Pakistan writes in her blog:
It almost seems to me that people in Pakistan do not want to develop; development is a looming monster that becomes a huge threat as soon as someone tries to push it forward. And rather than supporting and encouraging such brave humanitarians — like Parveen Rehman — who’d dedicated as well as put their lives on the line, to help the poorest in the region live better lives, they are instead murdered. And with them, all hopes and dreams for a better, more economically sufficient future, wither away too.