Chernobyl: 20 Years Later

An aerial photo of the Chernobyl nuclear power plant taken two or three days after the 1986 explosion which spread clouds of radioactive dust across the western part of the then-Soviet Union and Europe. Ukraine marks the 20th anniversary of the Chernobyl nuclear disaster, the world's worst-ever nuclear accident, on April 26, 2006.

A doll and a gas mask, covered by radioactive dust, are seen in an abandoned kindergarten in the ghost town of Pripyat, Ukraine, on March 10, 2006. Pripyat, built a mile from the Chernobyl nuclear power plant to house the plant's workers, was evacuated within hours of the April 26, 1986 explosion.

View of the sarcophagus covering the damaged Reactor No. 4 of the Chernobyl nuclear power plant on April 12, 2006, nearly 20 years after the 1986 explosion spewed radioactive clouds over the western part of the then-Soviet Union and much of Europe. Ukraine marks the 20th anniversary of the Chernobyl nuclear disaster on April 26, 2006. The explosion was the world's worst-ever nuclear accident.

View of an amusement park's Ferris wheel and empty apartment buildings in the abandoned town of Pripyat, Ukraine on March 10, 2006. Pripyat was home to the plant's workers, and the entire town of 47,000 was evacuated after the accident, with residents forced to leave behind their belongings and even pets. Ukraine marks the 20th anniversary of the explosion on April 26, 2006.

Children's toys and gas masks, covered by radioactive dust, are seen on bed frames in an abandoned kindergarten in the ghost town of Pripyat, Ukraine on March 10, 2006. Pripyat, built nearly a mile from the Chernobyl nuclear power plant to house workers, was evacuated within hours after the April 26, 1986 explosion.

Chernobyl's damaged Reactor No. 4 is seen from Pripyat, Ukraine on March 10, 2006. Pripyat was home to the plant's workers, and the entire town of 47,000 was evacuated after the accident, with residents forced to leave behind their belongings and even pets. Ukraine marks the 20th anniversary of the explosion on April 26, 2006.

The ghost town of Pripyat, Ukraine, built to house workers of the Chernobyl nuclear power plant, is seen through barbed wire on Monday, April 10, 2006. Pripyat was evacuated within hours of the April 26, 1986 explosion in Reactor No. 4 which sent a radioactive cloud through part of Europe.

Construction crews, wearing masks and special protective suits, work Monday, April 10, 2006, in high radiation levels to strengthen the crumbling sarcophagus that covers the Chernobyl nuclear power station's damaged Reactor No. 4. The crews can only work from four to 15 minutes because of the high level of radiation still emanating from the reactor, which exploded 20 years ago in the world's worst ever nuclear accident.

Olena, 7, has her thyroid tested for abnormalities on March 7, 2006, by a Red Cross unit that travels through rural areas in western Ukraine that were contaminated by the 1986 explosion at the Chernobyl nuclear power plant. Thyroid cancer rates have skyrocketed since the accident, and it is the main disease that the international community links to Chernobyl.

Taras, 6, a victim of after-effects of radioactive fallout from the 1986 Chernobyl disaster, listens during a protest organized by Ukraine's Chernobyl Union members, in Kiev, Ukraine, on Saturday, April 23, 2005. Ukraine is marking the 20th anniversary of the Chernobyl accident, which spewed a cloud of radioactive dust over huge chunks of Ukraine and Europe. Writing on Taras' hat reads "Chernobyl's children."

A Ukrainian woman is reflected in a mirror as she waits to be operated upon for thyroid cancer at the surgery section in a hospital in Kiev Thursday, April 6, 2006, Thyroid cancer rates have skyrocketed since the April 26, 1986, Chernobyl accident. Thyroid cancer is the one illness that all scientists agree is linked to the accident.

Ukrainian doctors operate on a patient suffering from thyroid cancer at the surgery section in a hospital in Kiev, Thursday, April 6, 2006. Thyroid cancer rates have skyrocketed since the April 26, 1986, Chernobyl accident. Thyroid cancer is the one illness that all scientists agree is linked to the accident. The world is marking the 20th anniversary of the explosion at the nuclear power plant.

A Ukrainian emergency official plays the guitar during a commemorative concert for the residents of the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, on Wednesday, April 5, 2006. Illintsi, like many villages surrounding Chernobyl, was evacuated days after the 1986 explosion, but the residents soon returned, ignoring warnings.

Villagers listen to a commemorative concert that Ukraine's emergency workers perform in the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, on Wednesday, April 5, 2006. Illintsi, like many villages surrounding Chernobyl, was evacuated days after the 1986 explosion, but the residents soon returned, ignoring warnings not to come back.

A Ukrainian emergency official plays the accordion during an amateur commemorative concert for the residents of the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, on Wednesday, April 5, 2006. Illintsi was evacuated days after the 1986 explosion, but the residents soon returned, ignoring officials' warnings.

Villagers listen to a commemorative concert that Ukraine's emergency workers perform in the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, on Wednesday, April 5, 2006. Illintsi, like many villages surrounding Chernobyl, was evacuated days after the 1986 explosion, but the residents soon returned, ignoring warnings not to come back.

A villager who gave only his first name, Mykhailo listens to a commemorative concert that Ukraine's emergency workers perform in the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, on Wednesday, April 5, 2006. On April 26, Ukraine marks the 20th anniversary of the world's worst nuclear disaster.

A Ukrainian man carries a bucket with water at the village of Zurin just outside the exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, Friday, April 7, 2006. On April 26, Ukraine will mark the 20th anniversary of the world's worst nuclear disaster.

Ukrainian children play next to their home in the village of Zurin just outside the exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, in Ukraine Friday, April 7, 2006. On April 26, Ukraine marks the 20th anniversary of the world's worst nuclear disaster.

A villager who gave only her first name, Antonina, points at her family photos in her house in the village of Illintsi in the so-called exclusion zone, a highly-contaminated 18-mile area surrounding the Chernobyl nuclear power plant, in Ukraine on Wednesday, April 5, 2006. Illintsi was evacuated days after the 1986 explosion, but the residents soon returned, ignoring officials' warnings.