NEW YORK—Doctors worked Monday to save the lives of multiple people gravely injured when smoke from a fire knocked them out or trapped them in their apartments in a New York City high-rise building. Nineteen people, including nine children, died in the blaze. Dozens of people were hospitalized, and Mayor Eric Adams said Monday morning that several people were in critical condition after Sunday’s fire in the Bronx, already the city’s deadliest in three decades. A somber mayor told CNN that the death toll could rise. “We pray to God that they’ll be able to pull through,” he said. Investigators determined that a malfunctioning electric space heater, plugged in to give extra heat on a cold morning, started the fire in the 19-story building. The flames damaged only a small part of the building, but smoke escaped through the apartment’s open door and turned stairwells—the only method of flight in …