A minivan rolled down a steep hill into a park pond Wednesday morning, killing a woman and two children on their way to a Fourth of July barbecue, fire and police officials said. A third child was in critical condition.

The woman, who was the driver and the mother of at least one of the children, had gotten out of the van, then noticed it was rolling away and jumped back in before it went into the water shortly after 10:30 a.m., Police Chief Bryan Norwood said.

The victims were trapped inside for 20 to 25 minutes before members of the Bridgeport police scuba team were able to pull them out. Rescuers tried to revive them before they were taken to local hospitals.

"It's a real tragedy for a family in Bridgeport," Mayor John Fabrizi said. "A day of sorrow for all Bridgeporters."

"It's horrible," Fire Battalion Chief Ismael Pomales said. "We've had children die before. That's probably one of the toughest things for any rescue person to deal with."

Pomales said the woman apparently got out of the van to ask directions to a Fourth of July barbecue, but police would not confirm that Wednesday night.

The names of the victims were not immediately released because officials were notifying relatives.

All three children were under 7 years old. A spokesman for Yale-New Haven Hospital said the surviving child, a 6-year-old boy, was in critical condition in the intensive care unit.

The van rolled about 60 or 70 yards into Bunnell's Pond at Beardsley Park, where many people gathered to celebrate the holiday.

Bridgeport Hospital spokesman John Cappiello confirmed that two of the children died. The third was transferred to Yale-New Haven Hospital.

The woman was taken to St. Vincent's Medical Center, where she also died, Pomales said.

People nearby tried to stop the van before it reached the pond, but could not, Pomales said. Fire personnel tried to rescue the people inside the van but could not get to them before the scuba team arrived.

The park was closed Wednesday morning while emergency crews worked but later reopened.

"It's a tragic end. What else can you say?" Cappiello said. "You wish you could talk about the fireworks and whatever else is going on. One of these things always happens on the holiday, but this is just bizarre."