Overnight rains end record-setting heat wave Predictions of fist-size hail and winds of up to 70 mph failed to materialize, and there was no repeat of the massive power outages that crippled parts of the District and its suburbs starting on June 29. Instead, a light rain was falling as of 8 a.m., and the thermometer read 74 degrees - a drop of nearly 30 degrees from midday Sunday. Metro officials said Green Line trains were running normally after a heat-related derailment Friday, and all weather-related restrictions had been lifted for the morning commute. Dominion Power said 23,000 customers lost service about 6:15 p.m. Sunday after storms and lightning struck in Northern Virginia, but the utility had reduced the number of outages to about 3,500 by 8 a.m. Monday. Pepco reported only about 300 outages in the District, Montgomery County and Prince George's County by 8 a.m. And forecasters predicted temperatures in the low to mid-80s all week, with thunderstorms possible every day. After the thermometer hit 105 on Saturday - one degree short of the all-time heat record - relief started to come as early as Sunday morning, when the temperature inched down to 102. But who could tell? It still seemed as if the region had been buried alive in heat, as if the air was an enemy. Many felt like they were trapped indoors; those who ventured outside planned movements between air-conditioned venues the way generals plan island-hopping campaigns. The heat wave had forced the cancellation of some outdoor events; sent people to pools, theaters, libraries or other air-conditioned ­oases; and even bent Metro's steel tracks enough to derail a Green Line train. By 9 p.m. Sunday, the temperature at Reagan National Airport was 84 degrees - 18 degrees below the day's high. Meanwhile, the front triggered a severe storm in Spotsylvania County, Va., that damaged three commercial buildings and a house, injuring at least seven people in a neighborhood at the county's northeastern edge, said Mark Kuechler, a county fire and rescue spokesman. Jared Klein, a National Weather Service meteorologist, said a decision would probably be made Monday on whether to survey the damage to determine whether it was caused by a tornado. Earlier Sunday, a 20-foot section pavement buckled in the heat on eastbound Route 50 in the Bowie area. Some vehicle damage was reported when the incident first occurred, state police Sgt. John Revel said. For much of the weekend, service was halted on part of the Green Line, after the derailment on Friday that Metro officials said was caused by the heat. On Sunday night, Metro restored service on a single track between the Fort Totten and Prince George's Plaza stations. Full service was restored for Monday morning. While some exasperated residents - including a Bethesda family menaced by what appeared to be a live wire down near their home - were still contacting Pepco and other utilities about restoring power lost more than a week ago, regional officials were beginning to assess the financial impact of the derecho and the heat wave.