At about 2145 Eastern time, the airplane was substantially damaged when it impacted the ground in a residential area shortly after takeoff. Night visual conditions prevailed. The private pilot and one passenger were seriously injured; the other two passengers sustained minor injuries. According to a witness, the airplane “barely cleared the trees,” continued the climb, descended, begin to climb again, and then descended out of their view. The passengers reported that the takeoff roll appeared to be “normal”; however immediately after becoming airborne, the airplane “settled down and would not climb,” began “scraping treetops,” the pilot adjusted the pitch attitude of the airplane, it began to climb again, and “settled down again.” The pilot told them they were “going in,” the airplane impacted a tree, impacted the ground, and then came to rest upright.