Updated

A teen driving on a tree-lined road in rural Connecticut lost control and crashed into a tree Tuesday afternoon, killing four high school students and seriously injuring another, authorities said.

Three of the victims were pronounced dead at the scene of the crash in Griswold, about 40 miles southeast of Hartford, said state police spokesman Lt. J. Paul Vance. Another was taken to a hospital and died there.

The survivor is hospitalized in critical condition, he said. It's not clear whether the driver was killed. Police are not releasing the victims' names until Wednesday morning, after their families are notified.

The teens all attended Griswold High School and included a senior, three juniors and a sophomore, said Philip Anthony Jr., first selectman of Griswold, a town of about 12,000.

"It's a traumatic tragedy from anyone's perspective," he said. "This is a small, close-knit community and we are officially in mourning. The grief is felt throughout the community."

Griswold School District Superintendent Paul Freeman declined to comment Tuesday night.

Investigators are trying to determine whether speed, alcohol or distracted driving were factors in the crash, as is typically done in motor vehicle accidents, Vance said.

The crash came a day after state officials held a news conference as part of Teen Safe Driving Awareness Week to highlight new requirements that they say improve safety.

Following several high-profile tragedies, Gov. M. Jodi Rell had created a task force on teen driving, which recommended more stringent laws that state lawmakers passed in 2008.

They included moving the teen driving curfew to 11 p.m. and doubling the amount of behind-the-wheel training required for teenagers.

There were six fatal crashes in Connecticut involving 16- and 17-year-old drivers in 2009, the lowest in 12 years.