Two kids were killed and two more are in critical condition after a barge appears to have struck their boat and sent them overboard during a sailing camp in Miami on Monday, authorities said.

All six people on the sailing boat were pulled from the water by responders, and four kids were rushed to a nearby hospital where two were pronounced dead upon arrival, said Petty Officer 3rd Class Nicholas Strasburg, a spokesperson for the U.S. Coast Guard.

The six — one adult and five kids — were in their last week of the sailing camp for kids from 7 to 15 years old, according to the Miami Yacht Club.

“The entire MYC family is devastated by this terrible tragedy,” said Emily Copeland, the commodore of the yacht club, in a statement.

Two of the six who were rescued were in “good condition," Strasburg said.

Last year, there were over 550 deaths in recreational boating, of which 43 were caused by vessels crashing into each other, according to Coast Guard statistics.

The boats collided near Star Island, which runs between Miami Beach and Miami in Biscayne Bay, said Arielle Callender, a regional spokesperson for the Florida Fish and Wildlife Conservation Commission, in a statement.

Local television stations showed first responders, some in scuba diving gear, in boats around what appears to be a barge. The Coast Guard is investigating the crash.