TANGIER, Morocco —  The bodies are anonymous, rotting in the shallows of the Straits of Gibraltar (search). The fortunate ones are dragged out for a hasty burial. They are Africans trying to make it to Europe, betting their lives on a nine-mile ride, thousands losing that bet each year.

Spain used to be an open door for illegal immigrants. An estimated one-quarter of all smuggled immigrants into Europe came through the Southern coast of Spain, most setting off from Morocco (search).

The sticks and stones of frustrated border guards had little effect against a rising tide of human traffic.

But all that changed on March 11. Most of the terrorists who killed 190 people on commuter trains in Madrid were Moroccan. Suddenly, the immigrant problem was a security problem.

Under pressure at home and from other European nations, rubber batons at the border were replaced by speedboats but success, so far, is limited.

"The numbers are down here by 50 percent," said Lt. David Oliva of the Spanish Border Guard. "But the smugglers are just moving to other parts of the coast."

Although only nine miles separate Africa from Europe, that stretch contains some of the most dangerous currents in the world. Now, some people in Africa are so desperate, they are ready to pay $1,000 a head just to get across, and they'll take their chances on anything that floats.

Seventy-five people from the Moroccan village of Tangier drowned trying to cross the waters last month. When FOX News approached families of the victims, they started to cry. One man lost 21 relatives.

With no electricity, jobs, education, or running water, there is nothing to do but wait for someone to get them out of the area. "These people are so desperate they are ready to die," said Khalil Jemmah, a Moroccan aid worker. "It's just a question of who gets here first, the smugglers or the terrorists."

More often than not, it's the terrorists who are getting there first.

It was a Moroccan who is accused of killing filmmaker Theo Van Gogh (search) in the Netherlands this month. The murder set off weeks of ethnic and religious clashes and skirmishes in Spain in what may eventually become a pan-European battle, fueled by the failure to integrate a new, illegal Muslim population.

Editor's Note: This is part one of a four-part series about the Muslim population in Europe. Tomorrow's installment will focus on how Sweden is handling a huge influx of Muslims.