Two people were killed in a plane crash Saturday evening in western central Alaska and four others on board survived, Alaska State Troopers said Sunday.

Trooper spokeswoman Beth Ipsen told local media that around 8:45 p.m. local time on Saturday, someone on the single-engine plane activated a spot beacon that transmitted a 911 signal, but rescuers could not reach the downed plane until around 11:00 a.m. Sunday due to heavy rain in the area.

The plane took off Saturday evening from McGrath, a city about 225 miles (362 km) northwest of Anchorage, largest city in Alaska, and was heading to the village of Anvik, which is 140 miles (225 km) west of McGrath.

The four survivors have been taken to McGrath by helicopter.

Troopers have not released the names of the passengers. Anchorage Daily News, a local newspaper, reported that the passengers included all three teachers from an Anvik school, which has 18 students including teachers' children.