In what officials called "a senseless act," a paramedic in Kansas City, Missouri, was fatally stabbed on Sunday -- allegedly by a patient that he was transporting to a hospital.

       Firefighter-Paramedic Graham Hoffman, 29 years old, had been with the Kansas City Fire Department since 2022.

       "Early Sunday morning, Firefighter Hoffman was critically injured after being stabbed in the chest, piercing his heart, while transporting a patient to a local hospital on what began as a routine medical call from the police," a statement from the city said. "His partner immediately initiated a crew emergency."

       He was rushed to North Kansas City Hospital, where he died from his injuries, Fire Chief Ross Grundyson said.

       "KCFD crews worked tirelessly to save Firefighter Hoffman's life en route to North Kansas City Hospital," the city's statement added. "Lifesaving efforts continued in the emergency room before Graham was moved into surgery. Despite the heroic efforts ... Firefighter Hoffman, succumbed to his injuries in the intensive care unit."

       Officials said the suspect was in custody on Sunday, but did not provide details.

       "I expect and will demand justice," Kansas City Mayor Quinton Lucas said at a news conference on Sunday. "I never expected a line of duty death like this one."

       "Graham was a dedicated professional who loved serving his city," the KCFD posted on Facebook. "He will be greatly missed."

       ABC News' Chris Barry contributed to this report.