Three people died and three others were hospitalized in critical condition after a white SUV struck pedestrians near a Los Angeles Metro station in North Hollywood on Tuesday evening, officials said. Police were investigating what caused the vehicle to hit people on the sidewalk.

The crash occurred at about 5:55 p.m. at the intersection of Lankershim and Chandler boulevards, according to Los Angeles police. At least five pedestrians were struck. The Los Angeles Fire Department said the three people killed could not be helped by arriving emergency crews and were pronounced dead at the scene.

Police Capt. Warner Castillo said the SUV's driver, a man in his mid-60s, was among those injured. Police drug-recognition experts went to the hospital to assess whether he was impaired. Castillo said investigators did not believe another vehicle was involved. Authorities had not established how fast the SUV was traveling.

Assistant Fire Chief Joe Everett said a fire department battalion chief encountered the scene around 6 p.m. and found that a vehicle had struck several people on the sidewalk. Police Chief Jim McDonnell also said everyone hit by the SUV had been on the sidewalk, while emphasizing that the investigation remained in its early stages.

Aerial footage aired by NBC Los Angeles appeared to show a white vehicle against the side of the Metro station, with debris spread across the surrounding area. The station contains stairs and escalators leading down to the subway. A witness told the broadcaster that the impact threw two women who were selling hot dogs into the air.

Mayor Karen Bass said those struck included pedestrians and vendors. Her office was working with city departments and other authorities to establish the cause. Bass expressed sorrow for the affected families and said further information would be shared as it became available.

McDonnell said investigators would review video and interview witnesses to reconstruct what happened. He said the inquiry would likely take time and would proceed deliberately. The police chief also expressed sympathy for the families of the people struck in the crash.

Los Angeles County Supervisor Kathryn Barger offered condolences to those who lost loved ones and wished the injured a recovery. In a statement, she expressed shock at the deaths in North Hollywood and sympathy for the victims, their families and others affected.