SAN DIEGO (FOX 5/KUSI) — The National Transportation Safety Board (NTSB) has opened up an investigation after a private plane owned by chemist and Scripps Research Institute CEO Peter Schultz disappeared over the Pacific Ocean, according to multiple reports.

The Cessna T240 Corvalis TTx departed from Ramona Airport on Sunday, July 13 around 1:50 p.m. with the intent to land at Montgomery-Gibbs Executive Airport.

It had flown just over 500 miles before the aircraft’s altitude sharply dropped about 470 miles off the coast of San Diego, according to data on FlightAware. The tail number of the aircraft was N636CS per registry information from the Federal Aviation Administration.

Air traffic controllers cleared the Cessna to land at Montgomery-Gibbs. However, the pilot did not respond, the NTSB told Affiliate KUSI in a statement.

According to data from the Aviation Safety Network, the aircraft was presumed to have been “destroyed.” The name of the pilot and whether there were any other people on board the plane have not been released.

The NTSB is currently investigating the circumstances surrounding the plane’s disappearance, according to a post on X. The agency told KUSI that a preliminary report is expected to be released within 30 days after the incident, with the final report to be released within 12-24 months.

This is a developing story. Check back for updates.