A preliminary report on the midair collision of two small planes over the Everglades that killed four people says no evidence of mechanical failure was found.

The report was released over the weekend by the National Transportation Safety Board.

The report says radar information shows the Cessna 172R and Piper PA-44 slammed into each other on Dec. 6 at about 4:30 p.m. at 2,000 feet in the air.

The Cessna was heading roughly southwest at 86 knots and the Piper was flying southeast at 126 knots when they collided.