One person was killed following a rollover accident on Intestate
37 during the morning commute, police said.  The victim,
described by police as a man in his late 40s, remained
unidentified, authorities said.  Several vehicles were involved
in the wreck, which closed the interstate's northbound lanes
shortly before 8 a.m.  The man, driving a white pickup and
allegedly speeding, lost control while trying to change lanes,
hit the median, went over a guardrail and tumbled down an
embankment next to the Alamodome near the Durango Street exit,
police said.  He was pronounced dead at the scene.  The lane
closures included the entrance ramp from Interstate 35 and
quickly caused a massive, miles-long tie-up on sections of both
interstates in the area just east of downtown.  The traffic also
made it difficult for emergency responders to make the scene and
for cleanup crews working to restore the roadway for use.