Two people died on Thursday after a helicopter they were on board crashed into a barge on the Mississippi River, shutting the waterway to traffic near Alton, Illinois, the US Coast Guard said.
Preliminary information indicated the MD 369 helicopter hit power lines before the crash, according to the National Transportation Safety Board.
The Federal Aviation Administration said there were two people on board when the helicopter crashed and the NTSB would lead the investigation. An NTSB investigator was expected to arrive on site on Friday, the agency said.
Power company Ameren Corp said a contractor and subcontractor were repairing and replacing tower lighting and marker balls on transmission lines.
"We are saddened about today's tragic incident," Ameren said, adding that it would cooperate with investigators.
No one was on board the barge, which caught fire after the crash, coast guard spokesperson Jonathan Lindberg said. Firefighters extinguished the blaze, he said.
The river, a major shipping waterway for crops and other goods, shut from mile marker 199 to mile marker 201, Lindberg said. There was no estimate for when the river would reopen, he said.
Alton is downriver from the Mississippi's confluence with the Illinois River, and the closure could delay barges carrying grain to the US Gulf from Midwestern farms.
(Reporting by Tom Polansek; Editing by Bill Berkrot and Jamie Freed)