(CNN) -- One of the main opposition videographers in Homs was killed on Tuesday as the Syrian city experienced its heaviest day of bombardment, residents and activists told CNN.
"Rami al-Sayed was crucial in getting the truth out through his videos posted on the Internet," said Omar Shaker, a friend and a volunteer at Homs Media Center, a media group set up by activists to share information and videos about the city's Baba Amr neighborhood.
"We will really miss him, especially the medical team who relied on him to document all the civilian injuries and deaths on video," he added.
Al-Sayed's own fatal injuries were also apparently recorded on Tuesday as his brother and a physician mourned his death at a mosque's basement. The video was later uploaded to Al-Sayed's YouTube channel.
In the video, Dr. Mohammed al-Mohammed stands by al-Sayed's dead body and says, "I want to bring you the latest news, the martyrdom of one of the most important cameramen and one of our most important journalists in Baba Amr."
"He kept bleeding here in the field hospital for more than three hours; we tried to evacuate him outside the neighborhood but to no avail," al-Mohammed added.
The 27-year-old was hit by rocket shrapnel as he tried to help a family flee bombardment, residents told CNN.
"Rami was killed because he was documenting and sending real-life stories from Baba Amr. Rami was killed because he was filming the facts; but we will have 1,000 Ramis. ... Our revolution will prevail," the doctor said as the camera zoomed in on shrapnel wounds on al-Sayed's chest, abdomen and legs.
The video-sharing site Bambuser released a statement Tuesday mourning al-Sayed's death, also referring to him as "Syrian pioneer," his nickname on various social media outlets.
"Rami Ahmad al-Sayed has been one of the bravest and forefront fighters in getting the world's attention on what's going on in Homs, Syria. This afternoon, cameraman and journalist Rami Ahmad al-Sayed did his last broadcast -- he and his three friends were soon after this killed by the Assad armed forces," the statement said.
CNN was unable to independently verify the circumstances of al-Sayed's death.
His last message to followers on Twitter was: "Baba Amr is facing genocide right now. I do not want people to simply say our hearts are with you! We need actions. We need campaigns everywhere inside Syria and outside Syria. We need all people in front of all embassies all over the world. In a few hours there will be no place called Baba Amr and I expect this to be my last message. No one will forgive you for just talking without any action!"
Al-Sayed, who had lost a cousin and a fellow videographer in December, is survived by his wife and an 18-month-old daughter.
CNN's Kareem Khadder contributed to this report.