A helicopter crash in Minnesota on Thursday resulted in “multiple fatalities,” local authorities said.

The Lino Lakes crash happened in a field near Main Street and Sunset Avenue around 5:30 p.m. local time (6:30 p.m. EDT) and caused “significant wreckage,” according to officials. The total number of casualties, however, has not been revealed.

“We can’t identify much based on what remains in the field,” Anoka County sheriff’s Cmdr. Paul Sommer reportedly said. “It’s basically charred-up debris.”

“It landed in an open field, but we’re very close to dense residential neighborhoods near here,” Sommer said Thursday night, Twin Cities Pioneer Press reported. He added that we were “fortunate it landed where it did.”

According to witnesses, there was a pop and the helicopter’s rotary blade stopped turning, causing the chopper to fall from the sky and crash into a cloud of smoke.

“I’m watching and I can see something falling to the ground, and I’m thinking, ‘That helicopter dropped something,’ and then when it hit the ground, you know, there was a huge fireball,” witness Ed Turner told CBS Local.

The Federal Aviation Administration and the National Transportation Safety Board are investigating the helicopter crash, an FAA spokeswoman reportedly said.

The crash is the second in the region within three weeks. On Sept. 17, a Robbinsdale-based North Memorial Health Care helicopter crashed in Alexandria, Minnesota, injuring three people — the pilot, a nurse and a paramedic. No patients were on board.