Police believe she headed to the Toledo and Holland area.
Prosecutors say he had a sexual relationship with a student.
Ashley Sayarath, David Sayarath were found dead in home.
Officials did not say what caused them to believe former student was a threat.
Authorities ask residents to be on alert for teen missing since Saturday.
State sets actual limit at 50 mph for road entering town.
Part of Severe Weather Awareness Week.
The left lanes in each direction were reopened as of 8 a.m.
Officers responded to a shooting about 2:15 a.m. on Burlingame Drive.
Woman, 19, and man, 30, are slain.