A minivan lurched off the road and killed members of a Lawrenceville family walking on a sidewalk after a Marlins game in Miami Saturday evening, police and fire officials said Sunday.

The family was walking back to their car after the baseball game. The driver of the Dodge Caravan, Raul Herberto Ortega Arias, 67, and three of the four pedestrians it struck died shortly after arriving at Jackson Memorial Hospital's Ryder Trauma Center, police said.

The three pedestrians killed included a 13-year-old girl, 14-year-old boy and 50-year old woman, according to Miami Fire Rescue Lt. Ignatius Carroll. The fourth pedestrian, a 10-year-old girl, remained in the hospital in extremely critical condition Sunday, police said.

A man distressed by the crash who may belong to the family was also transported to the hospital, although he did not appear to be physically injured, Carroll said.

Authorities said they would not identify the victims until their next of kin could be notified. It was unclear how they were related or why they were in Miami.

"Right now (authorities) are focused on how do you break the news to that 10-year-old girl who doesn't even know probably what happened yet," Carroll said.

It was not immediately clear whether the driver was killed by a medical emergency, such as a heart attack, or by the impact of the van striking a wall after hitting the walkers, Carroll said. Authorities are awaiting an autopsy.

Police told The Miami Herald the minivan driver may have had a heart attack or other medical problem before crashing the van through metal handrails in front of an apartment building.