Two men who appeared to be speeding in a van along the H-1 freeway viaduct near Honolulu Airport triggered a three-car crash Thursday night that sent an SUV plummeting 30 feet onto North Nimitz Highway, killing the SUV’s driver, police said.

Traffic investigators said speed appeared to be a factor in the 9:10 p.m. collision, but drugs and alcohol did not appear to be involved.

Investigators said a 65-year-old Waipahu man and his 30-year-old male passenger, also from Waipahu, were traveling at a “high rate of speed” when they collided into the rear of a vehicle being driven by a 26-year-old Honolulu woman. With her in the vehicle were her 10-month-old daughter and a 25-year-old man from California, police said.

The collision forced the female driver to veer into an SUV, which smashed into a guardrail before plummeting off of the viaduct and onto North Nimitz Highway, police said.

The driver of the SUV, a 48-year-old Aiea man, was pronounced dead at the scene.

The crash was Honolulu’s 54th traffic fatality of the year, compared to 47 at the same time last year.