( CNN ) -- A business jet crashed into a hangar at the Santa Monica Airport on Sunday . No one survived the crash and subsequent fire , but authorities did not immediately determine how many were on board . The twin-engine Cessna Citation ran off the right side of the runway after landing at 6:20 p.m. PT , said Federal Aviation Administration spokesman Ian Gregor . The hangar collapsed and was too unstable for firefighters to enter , said Captain John Nevandro of the Santa Monica Fire Department . `` It was an unsurvivable crash , '' Nevandro said . There was no communication with the pilot to indicate mechanical failure , Van McKenny , an investigator with the National Transportation Safety Board , said Monday at a news conference . He added that the agency has not confirmed the number of people on the plane and that the county coroner will release that information . Charles Muttillo , vice president of Morley Builders of Santa Monica , issued a statement Monday saying the company 's president and CEO and his son were believed to be on the plane . `` We are aware of a plane crash at Santa Monica Airport last night . While we do not have specific facts , we believe that our President and CEO , Mark Benjamin , and his son , Luke Benjamin , a Senior Project Engineer with us were on board , '' the statement read . `` We are unable to issue a further statement at this time . We will provide you with more updates as soon as we learn of them . Thank you . '' Various models of the Citation jet carry from seven to nine passengers , according to the manufacturer 's website . A witness , Charles Thomson , told CNN affiliate KCAL-TV a tire on the plane appeared to burst . `` It was n't an emergency landing , '' Thomson said . `` It was just a landing , and the tire popped afterwards . '' McKenny said he could not confirm that a tire was blown . The plane departed from Hailey , Idaho , an area popular for vacation homes , KCAL reported . Children among 4 killed when plane crashes in Connecticut houses . Pilots snooze at 30,000 feet in cockpit of 300-passenger plane . UPS pilots died of crash injuries , coroner says . CNN 's Dave Alsup and Janet DiGiacomo contributed to this report .
NEW : Building company CEO , his son , believed to be onboard , business says . NTSB investigators on scene , waiting until scene is safe to enter . Number of victims unknown ; jet could carry seven to nine people . Comment: