Oscar-nominated director John Singleton - known for films including Boyz N the Hood and his remake of detective movie Shaft - is in intensive care after suffering a stroke.
A family statement confirmed the influential film-maker fell ill in hospital on Wednesday.
"John is currently in the ICU and under great medical care," it read.
"We ask that privacy be given to him and our family at this time and appreciate all of the prayers".
The statement was signed by his family, including his four children.
Born in Los Angeles, Singleton acted as a trailblazer for African-American directors throughout the 1990s.
A graduate of USC School of Cinematic Arts, his debut feature, 1991's Boyz N the Hood - written when he was just 24 alongside producer Steve Nicolaides - addressed themes of inner-city violence in Los Angeles.
It was a breakout role for actors Angela Bassett, Nia Long and Cuba Gooding Jr (pictured below) - who went on to win an Oscar for Jerry Maguire. It also marked the film debut for rapper Ice Cube.
The film's success saw Singleton become both the first African-American and the youngest person ever to be nominated for the best director Oscar. He also received a second nomination for best original screenplay.
Long - who went on to star opposite Will Smith in The Fresh Prince of Bel-Air - discussed its impact at a 25th anniversary screening held by the Academy of Motion Pictures Arts and Sciences in 2016.
"It was important as a young actor to me that this feel real, because I knew what it was like go home from school and hear gunshots at night," she said.
Singleton went on to collaborate with Nicolaides on a number of later projects, including Poetic Justice (starring Janet Jackson and the late Tupac Shakur) and a remake of Shaft, starring Samuel L Jackson.
Singleton also produced 2003's 2 Fast 2 Furious. He pulled out of the upcoming Tupac biopic in 2015, eventually replaced by Steve McQueen two years later.
As soon as news broke of the stroke at the weekend, celebrities were quick to send their support on social media.
Rapper Snoop Dogg shared a picture of the pair together on Instagram, writing: "Pray 4 my brother."
Esteemed director Guillermo del Toro has also sent well wishes, describing Singleton as a "generous spirit".
Get well, John Singleton! Such a generous spirit- pic.twitter.com/fgm7gTjLSG— Guillermo del Toro (@RealGDT) April 20, 2019
Chicago Fire co-creator Derek Haas said: "John Singleton is a wonderful human. Get well!"
Actor Mark Wahlberg also sent his "prayers".
Saying prayers for my brother John Singleton today. 🙏❤️🙏— Mark Wahlberg (@markwahlberg) April 20, 2019
Meanwhile, Long wrote: "Praying hard this morning for my friend johnsingleton PULL THROUGH BABY."
In recent years, Singleton has accused Hollywood of trying to "homogenise" black film-making.
"They want black people to be who they want them to be, as opposed to what they are. The black films now — so-called black films now — they're great. They're great films. But they're just product," he told the Hollywood Masters Interview series in 2014.
"They're not moving the bar forward creatively … when you try to make it homogenised, when you try to make it appeal to everybody, then you don't have anything that's special."
Singleton has since focused on TV projects, directing episodes of Empire and American Crime Story, as well as acting as creator and executive producer on 2017's Snowfall.