ARVADA, Colo. The cause behind a small plane crash in an Arvada neighborhood earlier this month remains under investigation, officials wrote in a National Transportation Safety Board preliminary report released this week. The Beech V35A airplane crashed around 9:30 a.m. on June 7 around Oberon Road and Carr Street in Arvada. All of the four people aboard were seriously injured in the crash, and one of the passengers died the following day. NTSB: Plane in fatal Arvada crash needs more examinationAccording to the preliminary report, which was released Wednesday, the pilot had left the Centennial Airport in Englewood around 9:14 a.m. with the intention to fly to the Northern Colorado Regional Airport in Fort Collins. However, about 10 minutes after takeoff, the pilot reported engine oil pressure issues and asked to divert to the Rocky Mountain Metropolitan Airport in Broomfield. On his way to the Broomfield airport, the pilot was forced to land in a residential area of Arvada.Witnesses later told authorities they saw and heard the plane as it flew low over the neighborhood. The engine "did not sound normal," they said, according to the report, and they "described what they thought was white smoke coming from the airplane."The preliminary report found that the plane's left wingtip hit a 30-foot tree next to the roadway just before it landed on the road. The landing gear was not down, so the plane slid across the road and collided with a parked vehicle before stopping in a person's front yard. In total, it traveled about 400 feet between the tree to where it stopped, according to the preliminary report. All four people inside the plane were transported to the hospital. The woman who died was later identified as Melissa Brinkmann by her family. Brinkmann's family released the following statement on June 10:"Melissa Brinkmann was involved in the plane crash in Arvada, CO, on June 7, 2024.  On Saturday, June 8th, we said goodbye to our beloved Melissa, our daughter, our big sister, our mom, our best friend, our partner, our hero.  We ask for space and privacy to grieve this tremendous loss on our own terms. Melissa was bold, brave, loving, and a fierce champion of those she loved and she loved boundlessly. To know Melissa was to be inspired by her.  She elevated others and made this world a better place. We have been awe-struck and comforted by the countless messages, memories, and stories shared by the legions of people Melissa has impacted. We will be forever grateful to the first responders, bystanders, and medical staff who came to her aid, fought for her, and eased her passage from this life."Watch the full NTSB update from the day of the crash here: Pilot reported engine issue before Arvada plane crash: Full NTSB updateInvestigators found scars on the road and scraping from the bottom of the fuselage. After impact, the airplane caught fire, which ended up consuming most of the aircraft. This included instruments in the cockpit, so they were not evaluated in the preliminary report. The engine and airframe were transported for further examination because they had also been severely damaged by the fire. The engine was partially attached to the engine mounts and firewall, the engine case intact, the oil cap was secure and the oil quick drain was securely mounted to the oil pan with a safety wire present, the report reads. The cause of the crash remains under investigation and was not listed in the preliminary report, which did not find any pre-impact anomalies or failures. The report, which is publicly available among other preliminary and final aviation reports here, is available in full below.The NTSB uses a classification system for all civil aviation accidents. This one was labeled a Class 3, meaning: Investigators are seeking to identify the underlying cause of an accident An investigator-in-charge, and possibly other NTSB experts, may either travel to the scene and conduct other follow-ups or may also investigate the crash remotely. In the Arvada case, Alex Lemishko is the investigator in charge A final report will be made available to the public after a final technical review of the facts and analysis Findings from the investigation may be used to support recommendations, or the investigative team may work with industry stakeholders to resolve safety issues highlighted in the investigation