2 Coast Guard members shot dead on Alaskan island April 12, 2012 -- Updated 2226 GMT (0626 HKT) 2 Coast Guard members are killed at their station on Alaska's Kodiak island The Coast Guard has given few deails, saying it's trying to find out what happened An elementary school was put on lockdown after the shooting, as a precaution (CNN) -- Two Coast Guard members have been shot dead on an island off Alaska's coast, prompting the lockdown Thursday of their base and at least one nearby school. The Coast Guard offered few immediate details Thursday afternoon as to how, when or why two of its own were killed. Capt. Jesse Moore did acknowledge, though, "It is possible the suspect remains at large." "We are deeply saddened that we lost two shipmates," Moore said in a news release. This is a rare occurrence, and we are going to do everything possible to ensure we find out exactly what happened. The victims, who have not been identified by name, were members at the Coast Guard Communications Station Kodiak. That base is on what the city of Kodiak's website calls the second largest island in the United States, situated in the Gulf of Alaska about 250 miles southwest of Anchorage. The borough of Kodiak Island has about 13,600 people, according to the U.S. Census Bureau. Peterson Elementary School on the island went into lockdown mode, like the Coast Guard station itself, around 8:30 a.m. (12:30 p.m. ET) after school leaders got a call from military police, Principal Beth Cole said. By 11 a.m., they shifted to "lock in" mode -- allowing for more movement within the school, though lunch was still delivered to students in their classroom as a precaution, said Cole. No people were allowed in and out of the building all day.