At least two people were killed when two small planes collided in Northern California while trying to land at a local airport. The planes crashed at Watsonville Municipal Airport shortly before 3pm local time on Thursday, according to a tweet from the city of Watsonville. The city-owned airport does not have a control tower to direct aircraft landing and taking off. There were two people aboard a twin-engine Cessna 340 and only the pilot aboard a single-engine Cessna 152 during the crash, according to the Federal Aviation Administration. The pilots were on their final approaches to the airport before the collision, the FAA said. The FAA and the National Transportation Safety Board, which did not immediately have additional details, are investigating the crash. No one on the ground was injured. The airport has four runways and is home to more than 300 aircraft, according to its website. It handles more than 55,000 operations a year and is used often by recreational planes and agriculture businesses. Watsonville, near the Monterey Bay, is about 160 kilometres south of San Francisco. Pictures and videos posted on social media showed the wreckage of one small plane in a grassy field by the airport. One picture showed a plume of smoke visible from a street near the airport. The planes were about 61 metres above the ground when they collided, a witness told the <i>Santa Cruz Sentinel</i>.