INDIANAPOLIS, IN - Severe summer weather hampered the event schedule but not the performances of athletes Thursday at the AT&T USA Outdoor Track & Field Championships, held at Michael A. Carroll Stadium.

Qualifying rounds were held in a handful of open events before a mid- afternoon, 90-minute delay took hold due to severe thunderstorms and lightning. Action resumed after 4 p.m., only to be halted for good at 7:30 p.m. as another wave of thunderstorms and lightning swept in from the south.

In qualifying races that took place Thursday afternoon, 2005 Visa Champion Kerron Clement ran 49.32 to lead all qualifiers in the men's 400m hurdles, with defending world champion Bershawn Jackson running 49.60 to win his heat.

Top 400-meter qualifiers were #1 world-ranked Sanya Richards among the women (51.02) and world and Olympic 4x400m relay gold medalist Darold Williamson for the men (45.05).

Defending U.S. champion Khadevis Robinson shared the fastest qualifying time in the men's 800-meter heats with Jon Rankin, as both men ran 1:47.47. Carrie Messner led 14 athletes through qualifying in the women's 3,000-meter steeplechase with her time of 10:17.67.

As a result of the weather delay, the first round of the women's 100 meters will be held Friday at 11:30 a.m., with the men following at 11:45. Semifinal rounds are currently slated for 6:15 and 6:30 p.m., with the finals at 8:25 and 8:35 p.m. The men's 10,000-meter final now is scheduled for 9:05 p.m. on Friday, with the women's 10,000m final at 9:40; the women's javelin final will be contested at 6 p.m. The women's triple jump final, halted midway through competition, also will resume Friday.

The final stop of the 2006 Visa Championship Series, the AT&T USA Outdoor Championships will be televised live on ESPN2 from 6-8 p.m. on Saturday, June 24, and from 5-7 p.m. on Sunday, June 25. All times are Eastern.