Published: May 13, 2013 12:36 PM EDT
Updated: May 13, 2013 1:24 PM EDT

LEE COUNTY, Fla. - Investigators returned to a Lee County school bus corral where four buses went up in flames over the weekend.

Investigators with the Lee County Arson Task Force were spotted on scene at the depot off Buckingham Road Monday morning inspecting the charred vehicles.

Officials have not yet said whether the fire is suspicious nor have they specifically labeled it arson.

The blaze, which started just after 4:00 a.m. Sunday, destroyed nearly $500,000 in property.

Monday morning, the school district was without six buses, including the four buses that burned and two nearby ones that were taken aside to be inspected. Drivers without a bus were given a spare to pick up students. According to Lee Schools Transportation Director Robert Morgan, the only potential incovenience of the spare buses is the lack of air conditioning inside them.

As needed, he says, the bus manufacturer will also visit the site to investigate the possibility that the fire was caused by a malfunction.

Morgan says the bus corral is gated and locked at night and has a surveillance system. The video will be reviewed by investigators.