STUART, Fla. -

Police say an 11-year-old boy died when a sailboat caught fire in the waters of Stuart.

Police spokesman Brian Bossio tells The Palm Beach Post that Charlie Birely had autism and his parents tried to rescue him as the boat was engulfed in flames Sunday morning on the St. Lucie River.

Bossio says Brian Birely and Karen Laake were not able to save Charlie and made their way into a "small dinghy-type vessel" where they were rescued. Officers were unable to board the sailboat because of the fire's extreme heat.

Police say the parents were hospitalized in Miami. The family's hometown was not released.

Bossio says the state medical examiner's office was going over the wreckage Monday. City police are investigating the fire with several other agencies.