An explosion that destroyed 20 fireworks warehouses in China three months ago will probably dim night skies in the United States this Fourth of July. ...

The blast on Feb. 14 in the Chinese port city of Sanshui shook homes miles away and fireworks soared and burst in midair for more than 24 hours, according to local news reports. It is unclear whether anyone was harmed.

The accident led to a ban on fireworks shipments at all Chinese ports except two that are far from fireworks production areas, resulting in further delays. ...

The result, she says, is that exports of consumer fireworks from China are down 35 percent this year and professional display fireworks are down 40 percent. Many shipments have not even left factories in Liu Yang, a city in Hunan Province, where more than 95 percent of fireworks sold in the United States are made.

When fireworks shipments arrive at the shallow port of Beihai, they may sit on the docks for weeks waiting for transfer to cargo ships anchored outside Hong Kong harbor.

Only one shipping line, Maersk, will handle pyrotechnics after Hyundai Merchant Marine discontinued service following a blaze aboard one of its vessels carrying fireworks in 2006.