Authorities continue to investigate the circumstances surrounding a helicopter crash in Houston on Sunday evening that killed four people on board and sparked a massive flame within sight of homes. The privately owned Robinson R44 helicopter collided with a radio tower after taking off from Ellington Airport,

The lights on a Houston radio tower were reportedly “unserviceable” a few days before a helicopter crashed into it killing four people in a fiery explosion.

The private helicopter with four people on board, including a child, either struck a cable or the tower, Houston Police Chief J. Noe Diaz said at a news conference.