Sheriff's officials say two people died when a helicopter burst into flames as it crashed into a field in a Twin Cities suburb. The aircraft crashed near a residential area in Lino Lakes Thursday evening igniting into what Anoka County Sheriff's Cmdr. Paul Sommer described as a "large fireball."

Sommer tweeted Friday that there are two confirmed fatalities. No one on the ground was hurt.

Sommer described conflicting witness accounts of what happened to the helicopter before it crashed about 5:30 p.m. Some witnesses reported seeing the helicopter's blade stop turning before it "dropped out of the sky," he said. Others told authorities that the helicopter began to break up before hitting the ground and bursting into flames.

The Federal Aviation Administration and National Transportation Safety Board will investigate. Lino Lakes is about 17 miles north of downtown St. Paul.