Sept. 21 (UPI) -- The National Transportation Safety Board has started investigating multiple aircraft crashes that killed nearly a dozen people in four states over the weekend, officials said.
In the Indiana crash, three people died in a Piper PA-32 near the Glendale Airport.
Howard County Sheriff's Department Capt. Jordan Buckley said local officials will cooperate with the NTSB and Federal Aviation Administration on the investigation.
While the crash happened during a celebration called Glendale Days, officials said they weren't sure if the downed plane was connected with the event.
In Texas, two Louisiana couples died when a Piper PA-46 crashed.
Officials identified the victims as Kenneth Hix, 59; his wife Missy Lynn Hix, 59; Philip Ackel, 59; and his wife Pauline Ackel, 58.
Authorities said the plane attempted to make an emergency landing near the Hilltop Lakes Airport Sunday.
In Michigan, the Ottawa County Sheriff's Office said two people died when a Vans RV-9 aircraft crashed after takeoff Saturday, just south of I-196.
The victims were identified as Dale Deweese, 61, and Joyce Deweese, 59.
In Illinois, police said a man was killed when a Safari Rotorcraft helicopter crashed Saturday. Officials said the two-seat chopper collided with a storage facility.
Witnesses said they saw the helicopter make a circle before crashing into the facility and catching fire.