Several buildings on the Cal Poly campus were evacuated yesterday. San Luis Obispo City Fire Chief Keith Aggson said his department received a call about a possible toxic spill in one of the parking lots near the engineering buildings. According to one student, a yellowish substance that had a weird smell and left an odd taste in his mouth was bubbling from a pipe. Hazmat crews identified the yellowish liquid as hot water from the campus central plant boiler. The cause of the leak is under investigation.