On October 22, 1993, at 1020 central daylight time, N23487, a Cessna 150, registered to RG Aero Service, Inc., and flown by a private instrument pilot collided with a vacant building shortly after takeoff from the Downtown Kansas City Airport, Kansas City, Missouri, while on a personal flight. Visual meteorological conditions prevailed and no flight plan was filed. The airplane was destroyed and the pilot was seriously injured. The flight originated shortly prior to the accident. The pilot stated he flew the airplane into the Downtown Airport approximately 3 hours prior to the accident takeoff without any problems. The pilot reported he conducted an engine run-up and takeoff without incident. He reported that during the initial climb, the engine started to "miss out like a magneto was not firing" at which time he checked the magnetos, carburetor heat and fuel to no avail. The pilot recalled, "I was loosing altitude, I made it over the bridge I put approximately 15 degrees flaps to slow impact into poles and building." Two witnesses reported hearing the airplane start while on the ramp. Both reported that the engine ran rough, however, one of these witnesses stated it smoothed out when, "Mr. Cayton gave it more gas." The other witness stated the engine remained running rough as the pilot taxied out for takeoff. The witness who stated the engine smoothed out reported the airplane seemed to be going "slow" during the takeoff and it seemed to "strain to gain altitude." Two other witnesses reported seeing the airplane when it was airborne and both reported that it was having problems. According to the Kansas City Downtown Air Traffic Control Tower, the pilot of N23487 requested a takeoff on runway 19 from intersection Charlie. Air Traffic advised the pilot to use a Delta Intersection takeoff for more available runway and informed the pilot that by using a Delta intersection takeoff, he would have 3,100 feet of runway available. At 1017, N23487 was cleared for takeoff with a southeast departure. The airplane impacted the side of a vacant brick building at 208 Main Street in Kansas City. The airplane came to rest in an alley/parking lot area in the rear of the building. Both wings were separated from the airplane and fuel was reportedly draining from both wing tank areas. The airplane was removed form the accident site and placed in a hangar at the Downtown Kansas City Airport where it was inspected by two inspectors from the Kansas City Flight Standards District Office. According to the Inspector Statement the post accident inspection failed to reveal any defects of the engine or its accessories which would have resulted in a loss of power. (See Inspector's Statement for further detail.) Approximately 3 gallons of fuel were drained from he right wing tank which appeared free of water and contaminants. Integrity of the left tank was compromised due to impact damage, therefore this tank was void of fuel. The fuel lines from the wing tanks to the selector valve and from the carburetor to the fuel stainer were unblocked. The carburetor appeared in operable condition. The Inspector's Statement continued, "Inspection of the ignition switch revealed the metal cap protecting the magneto terminals was off the back of the switch and laying very close to the terminals. (See Photo) If this cap touches the terminals it would ground out the magneto. It could not be determined if the cap was loose prior to the accident."